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Journal of Nepal Dental Association (JNDA)
ISSN 2091-0142
Vol. 10, No. 2, July-December, 2009
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Journal of
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Vol. 10, No. 2, July-December, 2009, Pages 81-165
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EDITORIAL BOARD
Chief Editor
Dr. Siddharth Dixit
Section Editors
Dr. Suprabhat Shrestha, Orthodontics
Dr. Rita Singh, Periodontics
Dr. Bandana Koirala, Pedodontics
Dr. Punam Basnet Dixit, Conservative Dentistry & Endodontics
Dr. Jyotsna Rimal, Oral Medicine & Radiology
Dr. Dipak Thapa, Prosthodontics & Maxillofacial Prosthetics
Dr. Sudeep Acharya, Oral & Maxillofacial Surgery
Dr. Ashish Shrestha, Community Dentistry
Editorial Advisors
Dr. Praveen Mishra, MOE
Dr. Tri Ratna Manandhar, BPKIHS
Dr. Basanta K Shrestha, IOM
Dr. Surendra Man Shrestha, PDCH
Dr. Binod Acharya, KDCH
Dr. Pranay Khanal, MBKDCH
Dr. Hemant Kumar Halwai, UCMS-CODS
Dr. Lonim Prasai Dixit, NDA
Dr. Sameer Aryal, NDA
Managing Editor
Dr. Shyam K Maharjan
NDA EXECUTIVE COMMITTEE
20082010
President
Dr. Suraj Ram Bhakta Mathema
Vice President
Dr. Sachin Agrawal
General Secretary
Dr. Lonim Prasai Dixit
Treasurer
Dr. Sameer Aryal
Joint Secretary
Dr. Niranjan Sharma
Members
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Dr. Suraj Gurung
Dr. Pravindra Adhikari
Dr. Samriddhi Vaidya
International Advisors
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Dr. Sagun Chengappa, Australia
Dr. Sergei B Dmitrienko, Russia
Publication Assistant
Mr. Khagendra P Bhattarai
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Contents
Vol. 10, No. 2, July-December, 2009
Editorial
Systemic antibiotics and periodontal diseases
81-83
Singh R
Original Articles
Applicability of Bolton’s tooth size ratio for Nepalese population
84-87
Jaiswal AK, Paudel KR
Comparative evaluation of dimensional accuracy of addition silicone and condensation
silicone impression materials: An invitro study
88-96
Joshi PR, Bhat GS, Shenoy V
Assessment of periodontal status of rural Nepalese population using the community periodontal index
97-104
Pradhan S, Bhat MK
Spectrophotometric analysis of shade duplication of various recent ceramic system used for
porcelain fused to a metal crown: An invitro study
105-109
Das DK , Dong CX, Singh SK, Roy J
Dental arch length and arch symmetry analysis of Nepalese permanent dentition
110-114
Shrestha RM, Bhattarai P
Co-relation between the pattern of impaction of mandibular third molars with their associated pathologies 115-118
Nyachhyon P, Mahat A
Comparison of duration of orthodontic treatment with and without extraction among orthodontic patients 119-121
Bhattarai P, Shrestha RM, Mishra P
Metronidazole for the prevention of dry socket after removal of impacted mandibular third
molar in Nepalese patients
122-124
Pant N
Case Notes
Calcium hydroxide in management of large periapical lesion
125-127
Dixit PB, Acharya S, Prajapati I
Goldenhar syndrome: A report of a rare case
128-130
Dali M, Chacko V, Rao A
Use of toothbrush in maxillofacial surgery
131-132
Sagtani A, Sybil D
Non surgical endodontic retreatment following surgical endodontic failure: A case report
133-136
Gautam S, Thapa A, Pai ARV, Kundabala M
Pyogenic granuloma associated with bone loss: A case report
137-139
Singh VP, Nayak DG, Upoor AS
Orthodontic mini implant: Versatile application for clinical enhancement
140-146
Xia CS, Ding Y, Kafle D
Endodontic management of trumatized immature nonvital permanent anterior teeth: A case report
147-150
Pradhan RJ
Review Articles
The dental applications of titanium and its alloys: A review
151-157
Rodrigues S, Shenoy V, Shetty T, Jain N
Management of obstructive sleep apnea using oral appliances: A Review (Part I)
158-161
Kavitha PR, P Vivek, Bhat S
Management of obstructive sleep apnea using oral appliances: A Review (Part II)
Kavitha PR, P Vivek, Bhat S
JNDA Guidelines
162-165
Nepal Dental Associatio
Association
n and FDI celebrates
World Oral Health Day o
on
n 12th September 2009
NDA welcomes all doctors to be a part of the
11th Annual Dental Conference held on 12th September 2009
at Hotel Hyatt Regency and Post Conference CDE
by Professor James L Gutmann
(Jointly organized by NDA and Dentsply Academy)
on 13th September 2009 at Hotel Radisson, Kathmandu, Nepal
Journal of Nepal Dental Association (2009), Vol. 10, No. 2, Jul.-Dec., 81-83
Editorial
Systemic antibiotics and periodontal diseases
Singh R
Associate Professor, People’s Dental College & Hospital, Nayabazar
position in both medicine and dentistry if used with care
and prescribed appropriately.
Dr. Robert Genco once made the profound statement
that we were ‘at the end of the beginning of research
into human periodontal diseases’ (13th International
Congress on Periodontal Research, Osaka Japan,
1992). Despite huge advances in the last 18 years, we
still remain at the end of the beginning, rather than at the
beginning of the end. Although a tremendous amount of
effort has been expended over the past 30 years to elicit
the causative agents of periodontitis, rarely has a single
bacterial species been directly linked to periodontal
diseases as its single etiologic factor.
Management of severe types of periodontitis should not
rely solely on systemic antibiotics but upon a combination
of mechanical debridement possibly in conjunction with
surgery, subgingival administration of antiseptics by
dental professionals and patients, patients’ oral hygiene
efforts and effective and safe systemic antibiotics in
certain cases.
There is currently strong enough evidence to implicate
three microorganisms as etiologic agents of periodontal
diseases: A. actinomycetemcomitans, Porphyromonas
gingivalis and Tannerella forsythia. Periodontitis can and
does occur in the absence of any of the aforementioned
three identifiable periodontal pathogens. Associative
evidence has linked a number of different bacterial
species with destructive disease like Prevotella
intermedia, Fusobacterium nucleatum, Eikenella
corrodens, Campylobacter rectus, Eubacterium nodatum,
Peptostreptococcus micros, and various spirochetes.
There is some recent evidence that implicates certain
viral agents e.g. cytomegalovirus, Epstein–Barr virus,
papillomavirus, and herpes simplex virus, may have
a role in the initiation of periodontitis, most likely by
affecting the host response to the bacterial challenge.
Nevertheless, the primary host challenge and disease
initiator continues to appear bacterial in nature.
Mechanical debridement remains the cornerstone of
periodontal treatment. This is an absolutely essential
step in any form of periodontal therapy and is often
sufficient to control the progress of periodontal
disease in a majority of patients. However, for some
patients, mechanical instrumentation of the infected
area is not sufficient to control disease progression.
Failure to obtain a favorable response may be due to
inadequacy of the host’s immune response, the ability
of the pathogen(s) to escape, either by invading gingival
tissue or finding shelter in an unreachable site, limited
access, instrument availability, operator skill, or a host
of other possible factors. Nonsurgical scaling and root
planing may remove subgingival Campylobacter rectus,
but is frequently ineffective against Porphyromonas
gingivalis, Prevotella intermedia, Bacteroides forsythus,
staphylococci and enteric rods, and may not significantly
reduce Actinobacillus actinomycetemcomitans1. Often,
incorporation of an appropriate chemotherapeutic agent
in conjunction with mechanical instrumentation provides
an additional antimicrobial effect offering increased
opportunity to control disease.
Role of Systemic Antibiotics in Periodontal
Diseases
Systemic antibiotics enter the periodontal tissues and the
periodontal pocket via serum and can affect organisms
outside the reach of cleaning instruments or topical antiinfective chemotherapeutics. Systemic antibiotic therapy
can also potentially suppress periodontal pathogens
residing on the tongue or other oral surfaces, thereby
delaying subgingival recolonization of pathogens2.
Systemic antibiotics may even be required for eradication
of periodontal infections by A. actinomycetemcomitans
and other pathogens. Actively progressing periodontitis
Antibiotics, defined, as naturally occurring or synthetic
organic substances that, in low concentrations, inhibit or
kill selective microorganisms, are particularly useful in
combating severe periodontal infections. The wholesale
misuse of these drugs has led to the emergence of
resistant strains. Antibiotics are valuable and, in some
instances, life saving drugs. They can only retain this
81
J. Nepal Dent. Assoc. (2009), Vol. 10, No.2
to conventional therapy6. However, due to its propensity
for severe adverse effects, clindamycin-HCl should
only be prescribed following culture and sensitivity
testing. Many microorganisms continue to demonstrate
sensitivity to tetracyclines, particular doxycycline and
minocycline. The use of subantimicrobial doxycycline
as an adjunct to mechanical instrumentation with or
without the adjunctive use of an antibiotic should be a
consideration. The inhibition of the inflammatory process
and the downregulation of matrix metalloproteinases
may provide a quicker return to periodontal health7.
is virtually always associated with specific bacterial
infections and often requires the adjunctive use of
systemic antibiotic therapy. Single drug therapies with
penicillins, tetracyclines, metronidazole or clindamycin
have been used frequently in periodontal practice.
However, since periodontitis lesions often harbor a
mixture of pathogenic bacteria, drug combination
therapies have gained increased importance3. Valuable
combination therapies include metronidazole–amoxicillin
for A. actinomycetemcomitans and various anaerobic
periodontal infections and metronidazole–ciprofloxacin
for mixed anaerobic and enteric rod/Pseudomonas
periodontal infections. The tetracyclines have the
additional advantage of inhibiting collagenases.
Comprehensive treatment of periodontitis is very
different from the treatment of most bacterial infections.
It is important to realize that growth of bacteria in pure
cultures is very foreign to the way that the vast majority of
bacteria naturally grow. Growth of bacteria in the biofilm
is very different than the growth of a single pure culture
in a test tube or on an agar plate. The aggregation of
bacteria in a biofilm impairs the diffusion or may even
inactivate antimicrobial agents. High concentrations of
the active ingredient are needed before a beneficial
effect can be expected. Biofilm experiments indicate
that the necessary minimum inhibitory concentrations
of antimicrobial agents are at least 50 times (or even
210,000 times) higher than for bacteria growing under
planktonic conditions8.
There is no single periodontal therapeutic regimen that
will provide a beneficial response for all patients. It is very
unlikely that there ever will be. Prescription of systemic
antibiotic therapy in periodontics should be based upon
scientific data and not upon personal biases. Empirical
antibiotic therapy may be used for periodontal diseases
with known microbial causes, such as acute necrotizing
ulcerative gingivitis, which is caused by anaerobic
organisms and can be cured by metronidazole, and
early localized aggressive periodontitis, mostly involving
A. actinomycetemcomitans, which can be controlled
or eradicated by systemic metronidazole–amoxicillin
combination therapy.
The evidence available suggests that disadvantages
and safety aspects of systemic antimicrobial use in
the management of periodontal diseases significantly
outweigh the benefits. Antibiotic prescribing should be
the exception rather than the rule and, in the majority of
cases, only considered after conventional therapies have
been unsuccessful. Recommendations for periodontal
anti-infective therapy will undoubtedly be continually
revised along with the development of even better
understanding of the pathogenic periodontal microbiota
and the availability of new and more effective drugs to
control or possibly cure periodontal infections.
Wherever microbiological testing is unavailable,
metronidazole–amoxicillin combination therapy (250–
500 mg of each, three times daily for 8 days) may be
a reasonable antibiotic first choice in periodontics. The
metronidazole–amoxicillin combination is an appropriate
choice in about 70% of advanced periodontitis
patients4. However, the metronidazole–amoxicillin
combination does not affect Pseudomonas or enteric
gram-negative rods that inhabit approximately 14%
of advanced periodontitis lesions. The combination of
metronidazole and ciprofloxacin (500 mg of each, twice
daily for 8 days) can cure anaerobic, enteric rod and
A. actinomycetemcomitans periodontal infections and
promote subgingival overgrowth of streptococci able to
inhibit gram-negative pathogens5.
References
The evidence seems to favor the use of metronidazole/
amoxicillin. However, this is not a panacea for all patients.
Metronidazole has a number of unpleasant side effects
that are not well tolerated by some patients. Amoxicillin
is definitely contraindicated in patients with penicillin
hypersensitivities. Potentially pathogenic bacteria, such
as E. corrodens, may be resistant to both metronidazole
and amoxicillin. Other antibiotics clearly provide
significant benefits for specific situations. ClindamycinHCl remains effective against classic gram-negative
anaerobic rods associated with periodontitis refractory
J. Nepal Dent. Assoc. (2009), Vol. 10, No.2
82
1.
Renvert S, Wikström M, Dahlén G, Slots J, Egelberg J. On
the inability of root debridement and periodontal surgery
to eliminate Actinobacillus actinomycetemcomitans from
periodontal pockets. J Clin Periodontol 1990; 17: 351–5.
2.
Edwardsson S, Bing M, Axtelius B, Lindberg B, Söderfeldt
B, Attström R. The microbiota of periodontal pockets with
different depths in therapy-resistant periodontitis. J Clin
Periodontol 1999; 26: 143–52.
3.
Slots J. Systemic antibiotics in periodontics (Am Acad
Periodontol position paper). J Periodontol 1996; 67:
831–8.
4.
MJAMP, van Winkelhoff AJ, Douqué NH, Steures
RWR, de Graaff J. Microbiological and clinical effects
of metronidazole and amoxicillin in Actinobacillus
actinomycetemcomitans-associated periodontitis. A 2year evaluation. J Clin Periodontol 1994; 21: 107–12.
5.
Slots J, Feik D, Rams TE. In vitro antimicrobial sensitivity
of enteric rods and pseudomonads from advanced adult
periodontitis. Oral Microbiol Immunol 1990; 5: 298–301.
6.
Gordon J, Walker C, Lamster I, West T, Socransky S, Seiger
M, Fasciano R. Efficacy of clindamycin hydrochloride in
refractory periodontitis: 12-months results. J Periodontol
1985; 56 (Suppl.): 75–80.
83
7.
McCulloch CAG, Birek P, Overall CM, Aitken S, Lee W,
Kulkarni
Randomized controlled trial of doxycycline
in the prevention of recurrent periodontitis in high risk
patients: antimicrobial activity and collagenase inhibition.
J Clin Periodontol 1990; 17: 616–22.
8.
Anwar H, Strap J, Costerton J. Establishment of aging
biofilms: possible mechanism of bacterial resistance
to antimicrobial therapy. Antimicrob Agents Chemother
1992; 36: 1347–51.
J. Nepal Dent. Assoc. (2009), Vol. 10, No.2
Journal of Nepal Dental Association (2009), Vol. 10, No. 2, Jul.-Dec., 84-87
Original Article
Applicability of Bolton’s tooth size ratio for Nepalese
population
Jaiswal AK1, Paudel KR2
Lecturer, CODS, Universal College of Medical Sciences, Bhairahwa, 2Lecturer, Kathmandu Medical College & Teaching Hospital,
Sinamangal, Kathmandu
1
Abstract
Objectives: To test the applicability of Bolton’s method for use in Nepalese population and to compare the reliability
of present values against those of most commonly used values.
Materials and methods: The sample consisted of 60 Nepalese males and 60 females (total 120 subjects) aged
between 17 to 23 years. Subjects without any previous orthodontic treatment, fully erupted permanent teeth, and
with no dental anomalies were included in this study. The measurements of mesio-distal widths of teeth were
made on dental cast using digital caliper. Sample t test was used whenever necessary and the mean, range, and
standard deviation were calculated for the anterior ratio and overall ratio. The measured values were compared
with Bolton’s original values.
Results: The mean anterior “6” ratio for Nepalese subjects was found to be 79.46 with a standard deviation of
2.60. The values ranged from 68.75 to 89.17. The mean overall “12” ratio for Nepalese subjects was found to be
92.42 with a standard deviation of 1.80. The values ranged from 85.93 to 98.68.
Conclusion: Mean anterior tooth width ratios between Nepalese male and female samples were statistically
significant but mean overall tooth width ratios between Nepalese male and female were not statistically significant.
These findings suggest that a large number of Nepalese subjects presenting for orthodontic treatment possess a
Bolton’s tooth size discrepancy that may influence treatment goals and results.
Key words: Tooth size ratio, Bolton’s analysis, Digital caliper
Introduction
Prediction of accurate space has prime role in diagnosis
and treatment planning in Orthodontics. According
to Proffit and Fields1, space analysis should be done
accurately before any Orthodontic treatment. Tooth
size discrepancy is defined as a disproportion among
the sizes of individual teeth1. In order to achieve optimal
occlusion, ideal intercuspation, normal overjet and
overbite, maxillary to mandibular tooth width ratios must
be proportional in size. Bolton2 in 1958 evaluated 55
cases with excellent occlusions and developed Bolton’s
tooth size ratio for six anterior teeth and the overall ratio
for twelve teeth.
Since differences in tooth size have been reported with
ethnic groups9-12, most of the practitioners now disagree
to apply the methods developed from the different ethnic
groups.
The Bolton’s tooth size ratio develops from white
population (Caucasians), so its reliability is still
questionable when applied to different ethnic groups13,14.
So, it’s necessary to test the applicability of Bolton’s
tooth size ratio for Nepalese population to make accurate
diagnosis and treatment planning.
The objectives of the present study were to:
Similarly many authors have evaluated factors
associated with differences in the tooth width ratios. The
relationship between malocclusion type and tooth size
proportions has been reported3-8.
1. Determine the Bolton’s ratios for Nepalese subjects.
2. Determine the sexual differences in tooth size
between Nepalese males and females.
Correspondence
Dr. Alok Kumar Jaiswal, Lecturer, CODS, Universal College of Medical Sciences, Bhairahwa
E-mail: [email protected]
J. Nepal Dent. Assoc. (2009), Vol. 10, No.2
84
Maximum 10 pairs of casts were measured per day to
avoid errors by eye fatigue. All measurements were done
directly from unsoaped plaster models. Maximum mesiodistal width of each tooth was measured and recorded to
0.1mm. All measurements were taken perpendicular to
the long axis of the tooth with the caliper beak entering
the interproximal area from the buccal or occlusal
side15. Repeated measurements were performed to
minimize the possible errors. Intra-examiner reliability
was predetermined at 0.2mm as mentioned by Bishara
et al11. Bishara11,17 recommended that measurements
that varied by 0.2mm or less to be averaged and remeasurement was done for measurements that varied
more than 0.2 mm and the three measurements were
averaged.
3. Compare the ethnic difference in tooth size between
Nepalese and Caucasians.
Materials and methods
The samples for this study were collected from the
CODS,Universal College of Medical Sciences,Bhairahwa,
Nepal. A random sampling technique was used. The
subjects were informed appropriately and informed
consent was obtained. The samples included dental
impressions obtained from the students of the dental and
medical sciences. Total 120 subjects were selected (60
males and 60 females). In spite of the ethnic diversity in
the Nepalese population, we considered there was low
error in sample selection, because the students selected
for medical studies came from different parts of Nepal.
The mean, range, standard deviations were calculated
for the size of teeth. The Bolton anterior ratio and the
Bolton overall ratio were calculated and tabulated.
Inclusion criteria were, native Nepalese with Nepalese
phenotypical characteristics such as brown skin color,
black hair and eye color ranging from brown to black,
age ranging from 17-23 years and all permanent teeth
erupted(except third molar). Exclusion criteria were
subjects with proximal or occlusal wear, interproximal
caries or restorations, crowding, spacing or diastema,
any cross bite, any over retained deciduous tooth,
missing permanent tooth, deep carious tooth, any
hypoplasia or dental anomalies and any past history of
orthodontic treatment15,16.
Results
The results are summarized in Table 1 to 3. Table 1
reports the mean, range, and standard deviation of
the anterior and overall ratio in the Nepalese male and
female subjects.
Table 1 suggests there was significant difference
between sexes for the anterior ratio (P=0.0089), but
there was no significant difference for overall ratio (P=
0.88)
The alginate impressions were made by the well trained
dentists of CODS, Universal College of Medical Sciences,
Bhairahwa, Nepal. The impressions were poured using
dental plaster. Starrett digital caliper (0-150mm, 799A6/150, Starrett tools (Suzhou) Co. Ltd., China) providing
measurements to ± 0.01mm was used to measure the
mesio-distal dimension of all teeth. The teeth measured
included the mandibular and maxillary permanent
incisors, mandibular and maxillary permanent canines,
mandibular and maxillary first and second premolars,
mandibular and maxillary permanent first molars.
All measurements were made by single investigator.
The combined male and female anterior ratio and overall
ratio were calculated and tabulated in Table 2.
The mean anterior “6” ratio for Nepalese subjects was
found to be 79.46 with a standard deviation of 2.60. The
values ranged from 68.75 to 89.17. The mean overall
“12” ratio for Nepalese subjects was found to be 92.42
with a standard deviation of 1.80. The values ranged
from 85.93 to 98.68 (Table 3).
Table 1: Tooth size ratio of male and female in the Nepalese population
Ratio
Male
Range
Female
Mean
SD
Range
Mean
SD
P
Anterior Ratio
73.70
89.17
80.44
3.52
68.75
87.05
78.48
4.47
0.0089*
Overall Ratio
85.93
98.68
92.46
2.72
86.60
97.54
92.38
2.89
0.8808
SD, Standard deviation; *significant P value (P <0.05)
Table 2: Tooth size ratio male and female combined for Nepalese population
Mean
SD
Anterior Ratio
Ratio
68.75
Range
89.17
79.46
2.60
Overall Ratio
85.93
98.68
92.42
1.80
85
J. Nepal Dent. Assoc. (2009), Vol. 10, No.2
Table 3: Parameters obtained in the present study compared to the Bolton parameters
Ratio
Range
Nepalese
Mean
Caucasian
SD
Nepalese
Caucasian
Nepalese
Caucasian
Anterior Ratio
68.75
89.17
74.5
80.4
79.46
77.2
2.60
1.65
Overall Ratio
85.93
98.68
87.5
94.8
92.42
91.3
1.80
1.91
Discussion
The Bolton sample was obtained from 55 subjects with
excellent occlusion; 44 were orthodontically treated2. In
present sample, all subjects were untreated and some
had mild malocclusions. Therefore, a direct statistical
comparison between groups is disputable.
Nepalese population. Although such an analysis may
appear to be time consuming, the benefits would seem
to outweigh this minor inconvenience by allowing more
efficient diagnosis of problems, more specific treatment
planning, and good success rate in achieving optimal
occlusions.
Although in some studies the reported differences with
Bolton’s ratios were statistically significant, the clinical
relevance is questionable. Originally, Bolton2 suggested
that a ratio greater than 1 SD from his reported mean
values indicated a need for diagnostic consideration.
More recently, a clinically significant tooth width ratio
discrepancy has generally been defined as 2 SD outside
Bolton’s published mean ratio3,4,12.
Limitations
Further studies based on larger sample size, are
required to confirm the applicability of the results of the
present study.
Further study is required to test the applicability of Bolton
values on Nepalese population having different types of
Angle’s malocclusion.
By using the above definition, an anterior ratio below
73.9 or above 80.5 and overall ratio below 87.5 or above
95.1 would be considered as clinically significant. High
prevalence rate of an anterior tooth size discrepancy
more than 2 SD above Bolton’s mean was found for
Nepalese subjects (Table 3). Although the mean values
of Nepalese subjects in this study and those of the
Bolton study are nearly same, the ranges and standard
deviations of the Nepalese subjects significantly larger.
Similar findings were found by Crosby and Alexander3.
Acknowledgments
I would like to thank Prof. Dr. J. N. Sinha for his kindness
and support and Dr. Rahul, Dr. Reshu, Dr. Rama,
Dr. Bikash and Dr. Barsha who helped me with the
sample collection.
References
If cases with ratios greater than 2 SD away from Bolton’s
values truly represent a significant discrepancy, then a
large number of Nepalese subjects present with relative
tooth sizes that could potentially cause problems in
attaining an optimal occlusal relationship.
Conclusions
Mean anterior tooth width ratios between male and
female samples were statistically significant but mean
overall tooth width ratios between male and female
were not statistically significant. These findings suggest
that a large number of Nepalese subjects presenting
for orthodontic treatment possess a Bolton’s tooth size
discrepancy that may influence treatment goals and
results. In both the overall ratios and the anterior ratio,
the range and standard deviation were varied in the
present study than in Bolton’s study.
Thus it is probably necessary to do precise space
analysis based on our own data to make an accurate
diagnosis and treatment plan for orthodontics in
J. Nepal Dent. Assoc. (2009), Vol. 10, No.2
86
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Crosby DR, Alexander CG. The occurrence of tooth size
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Freeman JE, Maskeroni AJ, Lorton L. Frequency of Bolton
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Lavelle CL. Maxillary and mandibular tooth size in different
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Arya BS, Savara BS, Thomas D, Clarkson Q. Relation of
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study of tooth size and dental crowding. Am J Orthod
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Ta TA, Ling JY, Hagg U. Tooth-size discrepancies among
different occlusion groups of southern Chinese children.
Am J Orthod Dentofacial Orthop 2001;120:556-8.
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Buschang PH, Demirjian A, Cadotte L. Permanent
mesiodistal tooth size of French-Canadians. J Can Dent
Assoc 1988;54:441-4.
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Tong H, Chen D, Xu L, Liu P. The effect of premolar
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2004;74:508–11.
10.
Smith SS, Buschang PH, Watanabe E. Inter-arch tooth
size relationships of 3 populations: “does Bolton’s analysis
apply?.” Am J Orthod Dentofacial Orthop 2000; 117:16974.
14.
Al-Khateeb SN, Abu Alhaija ES. Tooth size discrepancies
and arch parameters among different malocclusions in a
Jordanian sample. Angle Orthod 2006;76:459–65.
15.
11.
Bishara SE, Jakobsen JR, Abdallah EM, Fernandez
Garcia A. Comparisons of mesiodistal and buccolingual
crown dimensions of the permanent teeth in three
populations from Egypt, Mexico, and the United States.
Am J Orthod Dentofacial Orthop 1989;96:416-22.
Legovic M, Novosel A, Legovic A. Regression equations
for determining mesio-distal crown diameters of canines
and premolars. Angle Orthod. 2003;73:3:314–8.
16.
Bernabé E, Flores-Mir C. Are the lower incisors the best
predictors for the unerupted canine and premolars sums?
An analysis of a Peruvian sample. Angle Orthod. 2005;
75:202-7.
17.
Bishara SE, Fernandez Garcia A, Jakobsen JR, Fahl JA.
Mesio-distal crown dimensions in Mexico and the United
States. Angle Orthod. 1986;56:315-23.
12.
Santoro M, Ayoub ME, Pardi VA, Cangialosi TJ.
Mesiodistal crown dimensions and tooth size discrepancy
of the permanent dentition of Dominican Americans.
Angle Orthod 2000;70:303-7.
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J. Nepal Dent. Assoc. (2009), Vol. 10, No.2
Journal of Nepal Dental Association (2009), Vol. 10, No. 2, Jul.-Dec., 88-96
Original Article
Comparative evaluation of dimensional accuracy of addition
silicone and condensation silicone impression materials: An
invitro study
Joshi PR1, Bhat GS2, Shenoy V3
1
Prosthodontist, Nepal Police Hospital, Kathmandu, 2Principal, Vyas Dental College, Jodhpur, India, 3Professor and HOD, Department of
Prosthodontics and Maxillofacial Prosthetics, Manipal College of Dental Sciences, Karnataka, India.
Abstract
Background: Amongst the silicone impression materials, the addition silicones are superior in accuracy and
dimensional stability. These days a wide range of condensation silicones are marketed with claims of equally good
results as addition silicones.
Aims and objectives: To evaluate and compare the time dependent dimensional accuracy and stability of addition
silicone and condensation silicone impression materials.
Materials and methods: Two addition-cured silicones (Reprosil, Dentsply/ Caulk, USA and Express XT, 3M ESPE,
Germany) and two condensation-cured silicones (Speedex, Coltene Whaledent, USA and Zetaplus, Zhermack,
Italy) were evaluated. A stainless steel master die simulating a three unit fixed partial denture preparation was
fabricated. For each brand of the impression material, 6 impressions were made and cast poured immediately. The
impressions were repeatedly poured at 1 h, 24 h, 48 h and 16 8 h. Interpreparation dimension and occlusogingival
dimension were measured in the recovered stone dies (Type IV, Kalrock) using a travelling microscope calibrated
to an accuracy of 0.001 cm.
Results: i) the addition silicone impression materials were superior in accuracy and dimensional stability in
comparison to condensation silicone; ii) at 1 hour of pour, all the materials tested seemed to have comparable
accuracy and dimensional stability; iii) the gypsum dies produced from the successive pours of all the tested
impression materials were generally larger in interpreparation distance and smaller in occlusogingival dimension
than the stainless steel master die, with the addition silicone demonstrating the smallest change.
Conclusion: The addition silicones have better dimensional accuracy and stability than condensation silicones.
An impression made from condensation silicone should be poured as soon as possible.
Key words: Accuracy, Addition silicone, Condensation silicone, Impression materials
Introduction
Accurate replication of tooth preparations and their
arch positions require impression materials that exhibit
good dimensional stability1. Nonaqueous elastomeric
impression materials, or elastomers, were developed
as an alternative to natural rubber during World War
II. There are currently four basic types of elastomeric
impression materials in use in the dental profession: (1)
polysulfide, (2) condensation polymerizing silicone, (3)
addition polymerizing silicone and (4) polyether.
a longer period of time. Other disadvantages of the
polysulfides include the need to use custom-made rather
than stock trays due to a greater chance of distortion, a
bad odor, a tendency to run down the patient’s throat
due to lower viscosity and the lead dioxide materials that
stain clothing. The polyether being hydrophilic absorbs
water or fluids. It is a rigid material with high modulus
of elasticity which makes it extremely difficult to remove
from undercut areas. High cost, short working and setting
time and high stiffness after setting limit their use2.
The polysulfides are good in surface detail reproduction
but they are dimensionally unstable when stored for
Polyvinyl siloxanes are highly accurate, have little
dimensional change after setting, moderately short
Correspondence
Dr. Pramod Raj Joshi, Nepal Police Hospital, Maharajgunj, Kathmandu, Nepal
E-mail: [email protected]
J. Nepal Dent. Assoc. (2009), Vol. 10, No.2
88
distance of 1.947 cm and ii) occlusogingival dimension
(height) of 0.794 cm.
working and setting time and excellent recovery from
deformation on removal3,4,4,5,6,7. The addition silicones
have overcome the disadvantage of polymerization
shrinkage over the condensation silicone as there is
no by-product release3, condensation silicone has
high polymerization shrinkage because of the release
of alcohol by-product2. Loss of the by-product leads to
measurable weight loss accompanied by shrinkage of the
impression material on storage8. However, these days,
a wide range of condensation silicones are marketed
with claims of equally good results as addition silicones.
In addition, various brands of condensation silicones
available in the market are economically feasible in
comparison to addition silicones.
Standard 2 mm thick stainless steel copings were
fabricated for each abutment with the purpose of
producing uniform space for wash materials in putty
impressions. For the purpose of impression making,
perforated stainless steel custom trays were fabricated
(Fig. 3). The tray was fabricated in such a way that the
edges of the tray fitted into the 2 mm deep orientation
ledges placed on the platform. In this way, the tray could
be repeatedly and consistently seated in a self limiting
way each time an impression was made so that there
was approximately 7.0 mm clearance between its inner
surface and the abutments.
Accuracy of impressions with repeated pours is of interest
clinically, because duplicate models are sometimes
desired. The dimensions of a model from a second
pour can be affected by continuing polymerization of
impression material and/by distortion of the impression
with removal of the first model9. The contribution of the
impression materials to a successful fixed partial denture
can be increased by selecting a material which is stable
enough to produce accurate casts from repetitive pours
of a single impression. ADA Specification Number 19
recommends a maximum negative change in dimension
of 0.5% after a minimum of 24 h10.
In this study, a total of four elastomeric impression
materials were evaluated: two brands of addition
silicones (Reprosil, Dentsply/ Caulk, USA and Express
XT, 3M ESPE, Germany) and two brands of condensation
silicones (Speedex, Coltene Whaledent, USA and
Zetaplus, Zhermack, Italy). All the materials, which were
commercially available and recommended for use in
making fixed partial denture impression, were stored at
manufacturers’ recommended temperatures before use
and were mixed at room temperature and humidity so as
to simulate their clinical use.
A two step putty-wash impression technique was used
for making impression of the metal die using all the
four types of impression materials (Table 1). The tray
adhesive supplied by the manufacturer was evenly
applied over the inner surface of the tray and extended
approximately 2 mm on the outer surface along the
periphery. To allow space for the wash thickness, 2 mm
stainless steel spacer was placed on the abutments
before making putty impression. Putty (base and
catalyst) was mixed according to the manufacturers’
recommended proportions, loaded into the tray and the
tray seated over the stainless steel die as guided by the
alignment ledges until firm contact was made, indicating
that seating had occurred to the predetermined degree.
All the materials were hand mixed, to get a homogenous
mix, at room temperature and placed within the working
time recommended by the manufacturer. After seating
the tray, the impression was held with gentle finger
pressure on the stainless steel master die for twice the
indicated setting time to assure complete polymerization
at room temperature. After the putty impression had
completely set, impression was removed vertically. Metal
spacers were carefully removed and the impressions
were examined.
The primary purpose of this study was to evaluate
and compare the dimensional accuracy and stability
of addition silicone and condensation silicone on
repeated pours of single impression at various time
intervals, viz, immediately, one hour, 24 hours, 48 hours
and one week (168 h) after making the impression.
The quantitative method was accomplished by
microscopically measuring two critical dimensions of
each stone die: (1) The interpreparation dimension (IP)
and (2) the occlusogingival dimension (height) of the
larger abutment (posterior).
Materials and methods
A machined standard stainless steel die preparation
with specific dimensions (Figs. 1 & 2) was made so as
to simulate a three-unit fixed partial denture situation
replacing a mandibular first molar. Two dimensions,
the interpreparation dimension and the occlusogingival
dimension were measured on the master die and
stone dies. In order to assess the linear change in the
interpreparation distance, cross-grooves were prepared
on the occlusal surfaces of the abutments as reference
points. In the molar abutment, a vertical line which was
used for assessing the vertical change in occlusogingival
direction, was inscribed along the occlusogingival
direction joining two circumferential lines which were 1
mm from the occlusal surface and 0.5 mm from the base.
The measurements of the reference lines on the stainless
steel master die were recorded as: i) interpreparation
After removal and allowing for a short period of elastic
recovery, light body material was introduced into the
prespaced putty impression. Express XT Light Body
impression material was available in automix syringe
89
J. Nepal Dent. Assoc. (2009), Vol. 10, No.2
tips and was dispensed using an automixing device. For
Reprosil Light Body, equal quantity of base and catalyst
paste were dispensed directly from the tubes on clean
glass slab according to the manufacturers’ instruction
and mixed with clean stainless steel spatula and the
application was done with an impression syringe. For
both the brands of condensation silicones, equal strand
lengths of base material and activator were dispensed
directly from the tubes on a clean glass slab according
to the manufacturers’ instruction and mixed with a clean
stainless steel spatula and the application was done with
an impression syringe. The impression was re-seated to
the predetermined position and held with gentle finger
pressure for an adequate amount of time to ensure that
setting reaction was complete before removal. Since
the reaction took place in room temperature, which was
lower than the mouth temperature, the tray was held
in place for a longer duration than the manufacturers’
recommendation to ensure complete polymerization.
After that, the impression was removed with straight pull
directed along the path of withdrawal of the preparations.
The impression was checked and impression with voids
and other inaccuracies were discarded.
and a mean was recorded for a particular dimension. To
eliminate individual variability, all measurements were
made by the same individual. A positioning device was
made so that the measurement made for occlusogingival
dimension on the stainless steel die and the stone
dies could be reproduced. The accuracy of casts was
expressed as percentage deviation from the standard
die values. The difference between the mean of the stone
cast (msc) and the mean of the stainless steel die (msd)
divided by the mean of the stainless steel die multiplied
by 100 was expressed as the percentage deviation from
the stainless steel die for each impression material at
each measurement location.
Percentage deviation =
Results
The mean (in cm) and standard deviation of
interpreparation and occlusogingival measurements for
silicone impression materials tested at various time are
listed in Table 2. In this Table, the relative accuracies of
first and second pours (0 h and 1 h) for the materials
tested are depicted for interpreparation measurement.
For all the tested materials, occlusogingival dimension
is relatively stable at 0 h. The interpreparation distance,
generally, increased for most stone dies compared with
the stainless steel master die for all the tested materials.
Occlusogingival dimension decreased for most of the
materials compared with the stainless steel die. Graphic
results of comparison of mean interpreparation and
occlusogingival measurements for all materials tested
with the master die are shown in Figs. 6 & 7.
To prepare die stone casts, a ratio of 23 ml water to 100 gm
die stone (Type IV, Kalrock) was used. It was first mixed
by hand to incorporate the water and then mechanically
mixed under vacuum for 15 sec. The mixture was placed
into the impression from one end in small increments
with a small instrument until it completely filled the tray.
While pouring, the impression was kept on a vibrator to
avoid any air bubble entrapment.
For each brand of addition silicone as well as condensation
silicone, six impressions were made giving a total of 24
impressions. All the impressions were poured with high
strength dental stone immediately after the impressions
were obtained. After 45 minutes when the stone cast
was completely set, a total of 24 casts were recovered.
Likewise, the impressions were poured successively at
1 hour, 24 hours, 48 hours and 1 week (168 h) after
the impressions were made and thus altogether 120
casts were made. Any cast which showed voids and
other inaccuracies were discarded and replaced. All
the casts were labeled with the first letter of the brand
name coding the brand of the material. Roman numbers
coded the sample number and Arabic numbers coded
the pouring time (Fig. 4).
Effects of time of pouring are shown in Table 3. There was
no statistically significant difference in mean percentage
change at each measurement (interpreparation and
occlusogingival) for all the materials at 0 h, 1 h, 24 h
and 48 h. Results of Kruskal Wallis Test indicated
statistically significant change at 168 h (p<0.05) at both
the dimensions for the materials tested. Graphic results
are presented in Figs. 8 & 9 as percentage change of
each measurement at various time intervals between
the materials tested.
Table 4 shows mean and standard deviation of
interpreparation and occlusogingival measurements
between various time intervals for silicone impression
materials
tested.
Regarding
interpreparation
distance, statistically significant differences were
recorded between 0-1 hour for Express XT (p<0.05).
Likewise, at interpreparation distance, statistically
significant differences were recorded for Speedex and
Zetaplus between 48 h to 168 h (p<0.05). Regarding
occlusogingival dimension, statistically significant
change was recorded for Zetaplus during 48 h to 168
h (p<0.05).
Before measurements were obtained, the casts were
allowed to air dry for at least 48 hours and were
carefully observed to verify the proper replication of
the reference lines. The dental stone casts at the
measurement locations were each measured with a
travelling microscope (Parco) capable of measuring to
0.001 cm (Fig. 5). Each measurement of the stone dies
was repeated three times to ensure its reproducibility
J. Nepal Dent. Assoc. (2009), Vol. 10, No.2
msc - msd
x 100
msd
90
m1
m2
PM
m4
M
m3
m7
m5
m6
Fig 1: Stainless steel die with
spacer
m1
m2
m3
m4
=
=
=
=
Fig 2: Diagram of stainless steel die with reference marks
interpreparation distance
occlusogingival distance (height)
distance between abutment preparation (10.5 mm)
occlusogingical dimesion of each died (9.5 mm)
m5
m6
m7
M
Fig 4: Stone dies
gingival diameter of molar die (10.5 mm)
gingival diameter of premolar die (7.5 mm)
plateform thickness (5 mm)
molar abutment, PM = premolar abutment
Fig. 5: Travelling Microscope
1.970
0.800
1.965
0.795
1.960
Reprosil
1.955
Height mean
IP mean
=
=
=
=
Fig 3: Impression Trays and
Final Impressions
Express XT
1.950
Speedex
1.945
Zetaplus
1.940
0.790
Reprosil
Express XT
0.785
Speedex
Zetaplus
0.780
0.775
1.935
0.770
1.930
0 hr
1 hr
24 hrs
48 hrs 168 hrs Master
model
0 hr
Fig 6: Comparison of mean interpreparation (IP) distance of
addition silicone and condensation impression materials with
master die
1 hr
24 hrs
48 hrs 168 hrs
Master
model
Fig 7: Comparison of mean occlusogingival dimension (height)
of addition silicone and condensation impression materials with
master die
0.50000
1.20000
1.00000
0.00000
0.60000
% Change
% Change
0.80000
Reprosil
Express XT
0.40000
Speedex
0.20000
-1.00000
Zetaplus
0.00000
-0.20000
HR
HR
HR
-0.50000
0 hr
1 hr
Reprosil
24 hr
48 hr
Express XT
168 hr
Speedex
Zetaplus
-1.50000
HR
HR
-2.00000
-0.40000
Fig 8: Comparison of mean percentage deviation of
interpreparation distance at different time intervals between
materials tested
Fig 9: Comparison of mean percentage deviation of
occlusogingival distance (height) at different time intervals
between materials tested
91
J. Nepal Dent. Assoc. (2009), Vol. 10, No.2
Table 1: The details of the products involved in the study
Serial
No.
1.
Materials
Express XT Putty Soft
Type
Manufacturer
Batch No.
Addition silicone
3M ESPE, Germany
P060626C, P060626B
3M ESPE, Germany
B263227, C264787
Dentsply/ Caulk, USA
060818
Dentsply/ Caulk, USA
060914
Express XT Light Body
2.
Reprosil Putty
Addition silicone
Reprosil Light Body
3.
Speedex Putty Base
Condensation silicone
Speedex Light Body
4.
Zetaplus (Putty)
Condensation silicone
Oranwash L (Light body)
Coltene Whaledent, USA
NI675
Coltene Whaledent, USA
0074657
Zhermack, Italy
34522
Zhermack, Italy
34467
Table 2: Mean and standard deviation of interpreparation distance and occlusogingival dimension (height) between
silicone impression materials tested.
Time (h)
0
1
24
48
168
Product
N
Interpreparation distance
Mean
Std. Deviation
(cm)
1.945
.002
Occlusogingival dimension (Height)
Mean
Std. Deviation
(cm)
.793
.002
Reprosil
6
Express XT
6
1.944
.005
.795
.004
Speedex
6
1.946
.008
.793
.007
Zetaplus
6
1.946
.008
.795
.007
Reprosil
6
1.947
.006
.795
.004
Express XT
6
1.948
.005
.793
.002
Speedex
6
1.948
.013
.793
.011
Zetaplus
6
1.949
.013
.792
.006
Reprosil
6
1.948
.004
.792
.005
Express XT
6
1.948
.002
.791
.011
Speedex
6
1.955
.010
.792
.006
Zetaplus
6
1.955
.006
.791
.013
Reprosil
6
1.950
.009
.791
.013
Express XT
6
1.950
.011
.793
.007
Speedex
6
1.957
.010
.790
.009
Zetaplus
6
1.959
.018
.788
.016
Reprosil
6
1.950
.034
.791
.007
Express XT
6
1.951
.005
.792
.015
Speedex
6
1.953
.012
.788
.011
Zetaplus
6
1.967
.031
.780
.020
J. Nepal Dent. Assoc. (2009), Vol. 10, No.2
92
Table 3: Mean percentage change of interpreparation distance and occlusogingival dimension (height) from master die
for silicone impression materials tested
Deviation
At 0 h
At 1 h
At 24 h
At 48 h
At 168 h
Product
N
Reprosil
Express
XT
Speedex
6
Interpreparation distance
Kruskal
Wallis
%
Std.
p value
Test
Change
Deviation
X2(3)
-.1000
.133
6
-.1500
.285
6
-.0500
.412
Zetaplus
6
-.0500
Reprosil
Express
XT
Speedex
6
.0000
6
.0500
.305
6
.0500
.697
Occlusogingival dimension
Kruskal
Wallis
%
Std.
p value
Test
Change
Deviation
X2(3)
-.1200
.325
.1200
.611
-.1200
.939
.428
.1200
.922
.351
.1200
.563
-.1200
.365
-.1200
1.470
.954
NS
.344
.925
NS
.473
Zetaplus
6
.1000
.708
-.2500
.804
Reprosil
Express
XT
Speedex
6
.0500
.246
-.2500
.649
6
.0500
.121
-.3700
1.471
6
.4109
.524
-.2500
.765
Zetaplus
6
.4109
.380
-.3700
1.695
Reprosil
Express
XT
Speedex
6
.1500
.464
-.3700
.682
6
.1500
.592
-.1200
.948
6
.5130
.543
-.5000
1.239
Zetaplus
6
.6160
.935
-.7550
2.114
Reprosil
Express
XT
Speedex
6
.1500
1.788
-.3700
.999
6
.2000
.279
-.2500
1.934
6
.3080
.643
-.7550
1.448
Zetaplus
6
1.0272
.590
-1.7630
2.553
4.239
2.336
8.050
.237
NS
.990
NS
.045
sig
.253
.969
NS
1.864
.601
NS
.302
.960
NS
.501
.919
NS
8.150
.043
sig
p = probability level (<0.05)
Table 4: Mean and standard deviation of interpreparation distance and occlusogingival dimension between various time
intervals of silicone impression materials tested
Product
Reprosil
Express XT
0h–1h
Interpreparation distance
Paired differences Wilcoxon
Signed
p value
Std.
Ranks
Mean
Deviation
Test Z
-.0020
.004
-.841
.400 NS
Occlusogingival dimension
Paired differences Wilcoxon
Signed
p value
Std.
Ranks
Mean
Deviation
Test Z
-.0013
.003
-.841
.400 NS
1 h – 24 h
-.0011
.0021
24 h – 48 h
-.0020
.006
-.736
.462 NS
.0018
.010
-.736
.462 NS
48 h – 168 h -.0003
.037
-.135
.893 NS
-.0001
.017
-.105
.916 NS
Duration
.007
-.105
.917 NS
.005
-.736
.462 NS
0h–1h
-.0041
.002
-2.049
.040 sig.
.0020
.006
-.674
.500 NS
1 h – 24 h
.0001
.005
-.211
.833 NS
.0011
.010
-.314
.753 NS
24 h – 48 h
-.0021
.010
-.314
.753 NS
-.0018
.012
-.105
.916 NS
48 h – 168 h -.0008
.009
.000
1.000 NS
.0016
.015
-.105
.917 NS
table 4 cont ...
93
J. Nepal Dent. Assoc. (2009), Vol. 10, No.2
table 4 cont...
Product
Duration
0h–1h
Speedex
Zetaplus
Interpreparation distance
Paired differences Wilcoxon
Signed
p value
Std.
Ranks
Mean
Deviation
Test Z
-.0020
.009
-.946
.344 NS
Occlusogingival dimension
Paired differences Wilcoxon
Signed
p value
Std.
Ranks
Mean
Deviation
Test Z
-.0005
.013
-.210
.833 NS
1 h – 24 h
-.0070
.010
-1.476
.140 NS
.0013
.008
-.526
.599 NS
24 h – 48 h
-.0020
.015
-.314
.753 NS
.0021
.009
-.406
.684 NS
48 h – 168 h -.0030
.018
-1.976
.047 sig
.0016
.015
-.105
.917 NS
0h–1h
-.0025
.007
-.946
.344 NS
.0030
.006
-1.051
.293 NS
1 h – 24 h
-.0036
.014
-.813
.416 NS
.0010
.015
-.315
.752 NS
24 h – 48 h
-.0045
.020
-.933
.528 NS
.0028
.026
-.526
.599 NS
48 h – 168 h -.0048
.025
-1.999
.045 sig
-.0008
.016
2.120
.041 sig
p = probability level (<0.05)
Discussion
which represents a linear change of approximately 79.82
μm greater than the standard. At 48 hours of repour,
interpreparation distance increased by 0.513% to 0.616%
for Speedex and Zetaplus when compared with the
master die. This represented an increase of 99.881 μm
to 119.935 μm from the master die. Similarly, at 1 week
of repour, for the same products, there was increase in
the dimension by 0.308% to 1.027% when compared
with master die. These values represented increase of
59.968 μm to 199.935 μm in comparison to the master
die. The increased deviation in interpreparation distance
for condensation silicone over the time period indicates
a possible loss of volatile constituents (alcohol) yielding
undesirable dimensional stability1. The study revealed
statistically significant difference in interpreparation
distance for both the products of condensation silicone
during 48 h to 168 h of repour (p<0.05). The difference
in the interpreparation distance between the master die
and stone models repoured at 24 h, 48 h and 168 h
for condensation silicone may be clinically important
because this change may result in fixed partial dentures
that are too long mesiodistally12.
Interpreparation dimension (IP)
Interpreparation distance for all the dies produced
immediately after making impression from Reprosil and
Express XT decreased by -0.15% to -0.1%, whereas, for
the same dimension, Speedex and Zetaplus revealed
a decrease of -0.05%. All the four materials seemed to
have comparable accuracy and dimensional stability at
1 hour of pour. At 1 hour of pour, Reprosil revealed the
highest accuracy with no dimensional variation (Table
3).
The interpreparation distance increased for most stone
dies compared with the stainless steel master die for
all the tested materials. The effect of repouring on the
interpreparation distance are shown in Figs. 6 & 8.
Linke et al11. studied six types of impression materials
and reported that the perimeter of the arch of the test
cast was larger than the standard reference model.
Gordon et al12. reported the interabutment distances
were greater for all dies using polysulfide, polyether
and addition silicone impression materials: a linear
change of 45 μm to 100 μm greater than the standard
was observed. Clinically, this change may result in fixed
partial dentures that are too long mesiodistally. On the
other hand, Craig13, in a study, stated that no statistical or
clinical differences existed in interpreparation distances
in relation to master dies. Johnson and Craig9 reported
small differences that were insignificant in interabutment
measurements when compared with the master model.
Nissan et al14. reported an increase of 0.009% to 0.1% in
the interabutment measurements.
Regarding addition silicone impression materials tested,
deviation in interpreparation distance ranged from -0.15%
to 0.20% for all times of pour, when compared with the
master die. These values represent a linear change of
-29.205 μm to 38.94 μm which has questionable clinical
significance. Consistent with previous studies on addition
silicone, the materials used in this study were found to
be dimensionally accurate even up to one week12. This
is advantageous because casts can be poured up to 1
week without concern for dimensional accuracies as in
the case when the impression needs to be sent to the
laboratory for pouring.
Repour at 24 h showed the minimal percentage variation
for addition silicone whereas condensation silicone
revealed 0.41% increase in the interpreparation distance
J. Nepal Dent. Assoc. (2009), Vol. 10, No.2
94
The increase in the interpreparation distances seen
may be explained by linear setting expansion of the die
material. The increase in these distances may also be
partially attributed to the impression material shrinkage
upon setting towards the adhesive coated tray 9. Because
of the constrain imposed by an effective adhesive on
uniform shrinkage upon setting, abutments in resultant
casts may tend to be at a greater distance apart than
actually were on the master die or in the mouth7.
materials; the addition silicone material demonstrated
the smallest vertical change ranging from -0.37% to
0.12%. These values represent a linear change of -29.37
μm to 9.528 μm. Hence, the addition silicone impression
materials tested were extremely stable over the 1-week
period. It is desirable to minimize the decrease in height
because a shorter model will produce a casting that is
short at the margins9. A considerable gap or space may
be detected when the die is undersized or short.
Occlusogingival dimension (height)
For pours immediately after making the impression and
at 1 hour, vertical change for addition silicone impression
materials and condensation silicone impression
materials ranged from -0.12% to 0.12% and -0.25% to
0.12% respectively. At 24 hours of pour, the change in
occlusogingival dimension for all the materials tested
ranged from -0.37% to -0.25% (Table 3). These values
are of less clinical significance, hence, all the four
materials seemed to have comparable accuracy and
dimensional stability during this period of time.
Conclusions
Within the limitations of this study, the following
conclusions can be drawn.
1. The addition polymerization silicone demonstrated
superior results in accuracy and dimensional stability
in comparison to condensation silicone impression
material. This material was extremely stable over
the 1-week period. Amongst the addition silicone
impression materials tested, Reprosil proved to be
highly accurate.
2. Addition silicone and condensation silicone
impression materials seemed to have comparable
accuracy and dimensional stability at 1 hour of pour.
For condensation silicones, the time interval between
pours should not be greater than 1 hour. One can
expect changes in dimensions of dies produced
from successive pours of condensation silicone.
Therefore, impressions made from condensation
silicone should be poured as soon as possible.
At 48 hours of repour, Speedex and Zetaplus showed
the change in occlusogingival dimension of -0.50% and
-0.755% respectively. These values represent a change
of approximately - 39 μm and -59.947 μm respectively.
For pours at 168 hours, Speedex and Zetaplus showed
the change in occlusogingival dimensions of -0.75% to
-1.763% (Table 3). These values represent a change of
approximately -59.947 μm and -139.982 μm respectively.
Table 4 reveals statistically significant difference in
occlusogingival distance for Zetaplus between 48 h to
168 h of repour (p<0.05). These values may be clinically
significant which may result in shorter castings made
from the stone dies.
3. The gypsum dies produced from the successive
pours were generally larger in interpreparation
distance and smaller in occlusogingival dimension
than the stainless steel master die, with the addition
silicone demonstrating the smallest change. Larger
interpreparation distance may result in fixed partial
denture that are too long mesiodistally, whereas,
smaller occlusogingival dimension may result in
shorter castings made from the stone dies.
The effect of repouring on the occlusogingival distance
are shown in Figs. 7 & 9. This study showed decrease
in vertical height when compared to the standard for all
impression materials tested which was in agreement
with Stackhouse15. Craig16, Linke et al.11 and Johnson
and Craig9 also reported shorter vertical heights in their
studies. Nissan J. et al.14, in a study, reported a decrease
of 0.8% to 3% in the occlusogingival measurements.
This phenomenon occurred because of contraction of
the impression material toward the tray walls, making
the stone dies wider in the horizontal aspect and shorter
vertically9,17. During polymerization reaction, impression
materials shrink toward the center of mass; the use of
tray adhesives, however, would redirect this shrinkage
toward the impression tray wall. In contrast, in a study
by Gordon et al.,12 a slight increase of vertical heights for
addition silicone impression was reported. Increase in
vertical height was also reported by Hung et al18.
References
The vertical change was found to be smaller for addition
silicone for all times of pour than for condensation silicone
95
1.
Ciesco JN, Malone WF, Sandrik JL, Mazur B. Comparison
of elastomeric impression materials used in fixed
prosthodontics. J Prosthet Dent. 1981; 45: 89-94.
2.
O’Brien WJ. Dental Materials and their selection. 3rd ed.
IL: Quintessence Publishing Co, Inc; 2002. p 90-112.
3.
Council on Dental materials, Instruments and Equipment:
Vinyl Polysiloxane impression material: A status report. J
Am Dent Assoc. 1990; 120: 595-6,598,600.
4.
Craig RG, Urquiola NJ, Liu CC. Comparison of commercial
elastomeric impression materials. Oper Dent. 1990;
15(3):94-104.
5.
McCabe JF, Storer R. Elastomeric impression materials.
The measurement of some properties relevant to clinical
practice. Br Dent J. 1980; 149(3):73-9.
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Wassell RW, Ibbetson RJ. The accuracy of polyvinyl
siloxane impressions made with standard and reinforced
stock trays. J Prosthet Dent. 1991 ;65(6):748-57.
12.
Gordon GE, Johnson GH, Drennon DG. The effect of
tray selection on the accuracy of elastomeric impression
materials. J Prosthet Dent. 1990 ;63(1):12-5.
7.
Idris B, Houston F, Claffey N. Comparison of the
dimensional accuracy of one- and two-step techniques
with the use of putty/wash addition silicone impression
materials. J Prosthet Dent. 1995; 74(5):535-41.
13.
Craig RG. Review of dental impression materials. Adv
Dent Res.1988; 2(1):51-64.
14.
Nissan J, Laufer BZ, Brosh T, Assif D. Accuracy of three
polyvinyl siloxane putty-wash impression techniques. J
Prosthet Dent. 2000; 83(2):161-5.
15.
Stackhouse JA Jr. The accuracy of stone dies made
from rubber impression materials. J Prosthet Dent. 1970;
24(4):377-86.
16.
Craig RG. Evaluation of an automatic mixing system
for an addition silicone impression material. J Am Dent
Assoc. 1985; 110(2):213-5.
17.
Johnson GH, Craig RG. Accuracy of addition silicones as
a function of technique. J Prosthet Dent. 1986; 55(2):197203.
18.
Hung SH, Purk JH, Tira DE, Eick JD. Accuracy of one-step
versus two-step putty wash addition silicone impression
technique. J Prosthet Dent. 1992; 67(5):583-9.
8.
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Wassell RW, Barker D, Walls AW. Crowns and other extracoronal restorations: impression materials and technique.
Br Dent J. 2002 29; 192(12):679-84, 687-90.
Johnson GH, Craig RG. Accuracy of four types of rubber
impression materials compared with time of pour and a
repeat pour of models. J Prosthet Dent. 1985; 53(4):48490.
10.
Council on Dental Materials and Devices: Revised
American Dental Association Specification no. 19 for
Non-aqueous, Elastomeric Dental Impression Materials.
J Am Dent Assoc. 1977; 94:733-41.
11.
Linke BA, Nicholls JI, Faucher RR. Distortion analysis of
stone casts made from impression materials. J Prosthet
Dent. 1985; 54(6):794-802.
J. Nepal Dent. Assoc. (2009), Vol. 10, No.2
96
Journal of Nepal Dental Association (2009), Vol. 10, No. 2, Jul.-Dec., 97-104
Original Article
Assessment of periodontal status of rural Nepalese population
using the community periodontal index
Pradhan S1, Bhat MK2
Professor, Department of Dental Surgery, Bir Hospital, National Academy of Medical Sciences, Kathmandu, Nepal, 2Professor,
Department of Periodontics, College of Dental Surgery, Manipal, India
1
Abstract
Background: Periodontal diseases are the most common and widespread chronic dental diseases worldwide.
It is mandatory to know the disease status and treatment needs of the target population, in order to establish
preventive community programmes and to treat periodontitis. Update information about the periodontal health
status of adults in Nepal is limited.
Aims and Objectives: To assess periodontal status of rural Nepalese population aged 35-44 years using
Community Periodontal Index (CPI) and to analyze oral hygiene status of the population according to methods
used for maintaining oral hygiene.
Materials and methods: In 1998, 300 residents of appropriate age were examined to assess their periodontal
status with Community Periodontal Index (CPI) and Loss of Attachment (LOA). Basic demographic information
was also collected according to WHO (World Health Organization) proforma.
Results: Among 300 subjects of 35-44 years of age, 156 (52%) were males and 144 (48%) were females. None had
healthy periodontium, only 0.3% had bleeding on probing (Code 1). Shallow pockets (Code 3) were most prevalent
at 41.67%, followed by calculus (Code 2) 37.33% and deep pockets in 20.33% of the surveyed population. 36%
had no loss of attachment (Code I), 29.67% had 4-5 mm attachment loss, 19.67% had 6-8 mm attachment loss,
11.33% had 9-11mm attachment loss and 3.33% had >12 mm loss of attachment.
Conclusion: The prevalence of periodontal disease in 35 – 44 year olds was high in this epidemiological study
for periodontal disease with CPI and LOA. Poorer periodontal health was observed in males, smokers with some
chewing habits and with poor plaque score.
Key words: CPI, Periodontal status, Smoking, Oral hygiene
Introduction
Periodontal diseases are the most common and
widespread chronic dental diseases worldwide. In
developing countries, with acute shortages of trained
dental manpower, high levels of unmet dental needs,
and a scarcity of economic resources about 75 to 80
percent of the population live in rural areas1. In order
to establish community programmes to prevent and
treat periodontitis, it is mandatory to know the disease
status and treatment needs of the target population.
The community Periodontal Index of Treatment Needs
(CPITN) was developed for this purpose by the
Oral Health Unit of the World Health Organization in
collaboration with the Federation Dentaire Internationale.
It is a simple, time-saving method of assessing the
treatment needs of a specified population group, and
has stood the test in a number of major epidemiological
studies on the prevalence of marginal periodontal
disease2,3,4. Simplifications to this index system have,
however, entailed increasing criticism and a demand
for more precise recording of periodontal parameters5,6.
Use of the CPITN for epidemiological purposes that is
to obtain estimates of the prevalence and severity of
destructive periodontal disease in a population7 must
necessarily be based on the assumption that loss of
periodontal support is accompanied by the formation of
deepened periodontal pockets. However, the presence
Correspondence
Dr. Shaili Pradhan, Professor, Department of Dental Surgery, Bir Hospital, National Academy of Medical Sciences, Kathmandu, Nepal
E-mail: [email protected]
97
J. Nepal Dent. Assoc. (2009), Vol. 10, No.2
An interview cum oral examination, with the help of a
proforma prepared for the study was conducted for the
collection of data. Personal data regarding each subject
was recorded on the proforma. The recording of data
was based on the “WHO Oral Health Assessment survey
form (Proforma)”. Since the information recorded was
to be computerized, appropriate codes were assigned.
The assessment of the periodontal status was carried
out using the Community Periodontal Index21. Prior to
CPI recording plaque score for all teeth was recorded
using Silness and Loe Plaque Index.
of deepened pockets is reported to overestimate the
periodontal attachment loss in some populations8
while in other populations the occurrence of deepened
pockets is reported to underestimate loss of periodontal
support9,10,11,12. It does not include any of the cumulative
manifestations of periodontal tissue destruction such
as attachment loss, alveolar bone loss and gingival
recession but only the pocket depth. Pocket depth is
indeed an important aspect since it directly influences the
composition of the bacterial flora13,14 even though it may
not establish the extent of attachment loss. However,
recent research has been increasingly interested in
attachment loss which determines the remaining tooth
support15,16. The loss of attachment in the furcation areas
could be more important than pocket depth per sextant17.
Some authors have therefore suggested that the inability
of the CPITN to assess the degree of attachment
loss is a serious handicap18; others have suggested
that a measure of gingival recession or attachment
loss measurement5,12,19,20 should be incorporated in
epidemiological studies involving the CPITN.
This study was carried out in 1998 by single examiner
(first author). Examination was based on the methods
and diagnostic criteria recommended by WHO21 .The
examination was carried out using the standardized
Community Periodontal Index (CPI) probe (‘TSR 621’
WHO Periodontal probe) for detection of signs of
periodontal disease. This tool has a 0.5 mm diameter
ball at its tip, a black band between 3.5 and 5.5 mm,
and coloured rings at 8.5 and 11.5mm from the tip. The
CPI scores applied on the index teeth were as follows:
presence or absence of gingival bleeding (CPI 1),
presence of calculus (CPI 2), periodontal pockets 4-5
mm (CPI 3) or periodontal pockets 6 mm + (CPI 4). In
addition, loss of attachment (LOA) was recorded for the
index teeth according to the following criteria: Loss of
attachment was measured only if the CEJ (CementoEnamel Junction) was visible, Loss of attachment 0-3
mm(Code 0), Loss of attachment 4-5 mm(Code 1), Loss
of attachment 6-8 mm(Code 2), Loss of attachment 9-11
mm(Code 3), Loss of attachment 12 mm or more( Code
4)21. The mouth was divided into six sextants: the right
upper posterior teeth (teeth 18-14), the upper anterior
teeth (teeth 13-23), the upper left posterior teeth (24-28),
the left lower posterior teeth(38-34), the lower anterior
teeth (33-43) and the right lower posterior teeth (44-48).
Two molars in the posterior sextants and teeth 11 or 31
in the anterior sextants were selected for examination
at six conventional sites: the mesiobuccal, mid-buccal,
distobuccal, mesiolingual, mid-lingual and distolingual
surfaces. The highest of the component scores for each
sextant was taken to be the overall sextant score, and
the highest of the sextant scores for each individual to
be their overall assessment of periodontal disease.
The Community Periodontal Index (CPI) recommended
by WHO21, which also considers loss of attachment is
taken into consideration in this study conducted in rural
area of Nepal. Update information about the periodontal
health status of adults in Nepal is limited. According to
the data obtained from WHO Global Oral Data Bank,
the periodontal health of Nepalese population is poor.
Hence this study was undertaken in a rural Nepalese
population with no access to preventive or therapeutic
dental services.
The aims of the present study were to assess the
periodontal status of Nepalese rural adult population
using CPI and to analyze oral hygiene status of the
population according to the method they use for
maintenance of their oral hygiene. Furthermore, the
intention was to correlate other possible variables which
may have an influence on the periodontal status.
Materials and methods
Study area and population
Jhor Mahankal, a village situated in Kathmandu district
of Nepal was selected for the study. The selection of
this village was based on certain logistic considerations
like it is situated on the outskirts of Kathmandu valley,
about 16 Km from the main city and has population of
3360 with a favourable sex ratio of 1700 males for 1660
females. The population residing has limited tradition for
oral hygiene and very limited access to dental health
care facilities.
Prior to analysis of the data collected, the subjects were
assigned to various groups on the basis of their oral
hygiene practices or teeth cleaning devices, smoking
habits, chewing habits and plaque score.
Data analysis
The collected data was analyzed using the statistical
package SPSS/PC + and Chi Square test was applied
for comparing the associations. A p value of less than
0.05 was considered as significant.
Study Design
A total population of 300 subjects of 35-44 years
were chosen by random sampling technique and
were examined at their houses selected randomly.
J. Nepal Dent. Assoc. (2009), Vol. 10, No.2
98
had calculus, 42.86% had shallow pockets and 20.41%
had deep pockets, 32.65% had no loss of attachment,
40.82% had 4-5 mm loss of attachment, 18.37% had
6-8 mm loss of attachment, 8.16% had 9-11mm loss
of attachment and none had loss of attachment ≥ 12
mm. Among the subjects using other methods, 25.56%
had calculus, 48.12% had shallow pockets and 26.32%
had deep pockets, 19.55% had no loss of attachment,
31.58% had 4-5 mm loss of attachment, 26.32% had
6-8 mm loss of attachment, 17.56% had 9-11 mm loss
of attachment and 5.26% had loss of attachment ≥ 12
mm. (Table 2)
Results
In the present study, out of total number of 300 subjects
of 35-44 years of age, 156 (52%) were males and
144 (48%) were females. Among the total population
examined none had healthy periodontium, only 0.3%
had bleeding on probing (Code 1). Shallow pockets
(Code 3) were most prevalent at 41.67%, followed by
calculus (Code 2) 37.33% and deep pockets in 20.33%
of the surveyed population. (Table 1) 36% had no loss
of attachment (Code I), 29.67% had 4-5 mm attachment
loss, 19.67% had 6-8 mm attachment loss, 11.33% had
9-11mm attachment loss and 3.33% had >12 mm loss of
attachment (Table 2).
The results suggest that the amount of periodontal
destruction exhibited by the subjects using the
toothbrush were less than the destruction observed in
those using tooth powders, charcoal, ash and sand. This
was demonstrated by the lesser percentages of deep
pockets and higher percentages of subjects without
loss of attachment among the subjects using tooth
brush (p < 0.0001). When plaque score was correlated
with oral hygiene devices, it was observed that among
tooth brush users, 71.43% had lesser plaque score and
28.31% had fair plaque score while 25% of the subjects
had poor plaque score. Among tooth powder and finger
users, 20.09% had fair plaque score and 6.49% lesser
plaque score. Among those who used other devices,
75% had higher (poor) plaque score, 51.60% had fair
plaque score and 22.08% with lower (good) plaque
score (Table 3).
Gender
It was observed that among the males none had healthy
periodontium and bleeding on probing (Code 1), 29.49%
had calculus (Code 2) as the highest score, 44.23% had
shallow pockets (Code 3) also and 26.26% had deep
pockets (Code 4). Among the females, none had healthy
periodontium, 0.69% had only bleeding on probing,
45.83% had calculus as their highest score, 39.58%
shallow pockets and 13.89% had deep periodontal
pockets (Table 1).
In relation to the loss of attachment (gingival recession),
it was observed that among males 30.77% had no loss
of attachment, 32.05% had 4-5 mm loss of attachment,
17.95% had 6-8 mm loss of attachment, 12.82% had 911 mm loss of attachment and 6.41% had ≥ 12 mm loss
of attachment while for the females, 41.67% had no loss
of attachment, 27.08% had 4-5 mm loss of attachment,
221.53% had 6-8 mm loss of attachment, 9.72% had
9-11 mm loss of attachment and none had loss of
attachment exceeding 12 mm or more. (Table 2) The
above study suggests that the prevalence of periodontal
disease was more in males in comparison to females.
Plaque score
Among the study sample, 25.67% had lower plaque
score, 73% had fair plaque score and 1.33% had higher
plaque score. Among the subjects who had lower plaque
score, 1.30% had bleeding on probing (Code 1), 58.44%
had calculus, 25.97% had shallow pockets and 14.29%
had deep pockets (Table 1), 55.84% had no loss of
attachment, 19.48% had 4-5 mm loss of attachment,
14.29% had 6-8 mm loss of attachment, 6.49% had 9-11
mm loss of attachment and 3.90% had ≥ 12 mm loss
of attachment (Table 2). Among the subjects who had
fair plaque score, 30.59% had calculus, 47.49% had
shallow pockets and 21.92% had deep pockets, 29.68%
had no loss of attachment, 33.33% had 4-5 mm loss
of attachment, 21.46% had 6-8 mm loss of attachment,
12.79% had 9-11 mm loss of attachment and 2.74% had
≥ 12 mm loss of attachment. Among the subjects who had
higher plaque score, 50% had shallow pockets and 50%
had deep pockets, none had loss of attachment, 25%
had 4-5 mm loss of attachment, 25% had 6-8 mm loss
of attachment, 25% had 9-11 mm loss of attachment and
25% had ≥ 12mm loss of attachment. It was observed
that the subjects with lower plaque score had healthier
periodontal tissues than the subjects with fair or higher
plaque score. (p<0.0001)
Teeth Cleaning Devices/ Oral Hygiene Practices
The population was divided into three groups according
to the devices they use to clean their teeth, Group I who
used tooth brush constituted 39.33%, Group II who used
tooth powder with finger constituted 16.33% and Group
III other methods like charcoal, ash and sand constituted
44.33%.
In the distribution of periodontal status it was observed
that none had healthy periodontium and the groups
who used other methods had more attachment loss.
Among tooth brush users (Group I), it was observed that
0.85% had bleeding on probing (Code 1), 50.85% had
calculus, 34.75% had shallow pockets and 13.56% had
deep periodontal pockets (Table 1), 55.93% had no loss
of attachment, 22.88% had 4-5mm loss of attachment,
46.61% had 6-8mm loss of attachment, 5.93% had 9-11
mm loss of attachment and 2.54% had loss of attachment
≥ 12 mm. Among tooth powder with finger users, 36.73%
99
J. Nepal Dent. Assoc. (2009), Vol. 10, No.2
Smoking
In the population studied, 31% were none smokers
and 69% were smokers. Among smokers, 41.4% were
light smokers (those smoking less than 10 cigarettes a
day) and 27.3% were heavy smokers (those smoking
10 or more than 10 cigarettes a day). It was observed
among non smokers, 1.06% had bleeding on probing
(Code 1), 57.45% had calculus, 34.04% had shallow
pockets and 7.45% had deep pockets (Table 1), 56.38%
had no loss of attachment, 14.89% had 4-5 mm loss
of attachment, 23.40% had 6-8 mm loss of attachment
and 5.332% had 9-11 mm loss of attachment. None
had loss of attachment ≥ 12 mm. (Table 2) Among
light smokers, 29.03% had calculus, 50% had shallow
pockets and 20.97% had deep pockets, 25% had no loss
of attachment, 37.90% had 4-5 mm loss of attachment,
20.16% had 6-8 mm loss of attachment and 13. 71%
had 9-11 mm loss of attachment and 3.23% had loss of
attachment ≥ 12 mm. Among heavy smokers, 26.83%
had calculus, 39.02% had shallow pockets and 34.15%
had deep pockets, 29.27% had no loss of attachment,
34.15% had 4-5 mm loss of attachment, 14.63% had 6-8
mm loss of attachment an 14.63% had 9-11 mm loss of
attachment and 7.32% had ≥ 12 mm loss of attachment.
It can thus be concluded that the non smokers had better
periodontal status than smokers (p<0.00001).
of attachment, 24.24% had 6-8 mm loss of attachment,
18.18 % had 9-11 mm loss of attachment and 12.12
% had ≥ 12 mm loss of attachment. (Table 1 and 2)
The results indicate that the non chewers had better
periodontal status than chewers. (p<0.00001)
When chewing habit was correlated with plaque score,
it was observed that among those who had lower
plaque score, 28.79% were chewers and 24.79% were
non chewers. Among those who had fair plaque score,
73.50% were non chewers and 71.21% were chewers.
1.71% of non chewers had higher plaque score (Table 3).
It was thus demonstrated that various factors like the
oral hygiene practices, smoking, tobacco chewing
influenced the state of the periodontal tissues. To study
their effects in better detail smoking, chewing habits
and plaque score were correlated with the oral hygiene
practices. The results were as follows:
A correlation of smoking habits with oral hygiene
practices revealed that the majority of non smokers
(56.38%), 37.10% of light smokers and 23.17% of heavy
smokers used tooth brush. 19.51% heavy smokers,
16.94% light smokers and 12.77% non smokers used
tooth powder with finger. The majority of heavy smokers
(57.32%), 45.97% light smokers and 30.85% of non
smokers used other devices (Table 3) (p < 0.0001).
A correlation of smoking with plaque score showed
that, 44.48% of non-smokers, 20.16% of light smokers
and 12.20% of heavy smokers had lower plaque score.
Among those who had fair plaque score, 87.80% of
heavy smokers, 77.42% of light smokers and 54.25% of
non-smokers had fair plaque score. Among those who
had higher plaque score, 2.42% were light smokers and
1.06% were non-smokers (Table 3) (p<0.00001).
A correlation of chewing habits with oral hygiene practices
showed that relatively equal proportion of both chewers
(39.74%) and non chewers (37.88%) used tooth brush.
31.82% of chewers and 11.97% of non chewers used
tooth powder and finger. 48.29% of non chewers and
30.30% of chewers used other devices to clean their
teeth (Table 3) (p < 0.00001).
Chewing habits
Among the study sample 22% had oral habits like
tobacco and betel nut chewing and 78% did not. It was
observed that among non chewers, 0.43% had bleeding
on probing (Code 1), 39.74% had calculus, 38.89% had
shallow pockets and 20.94% had deep pockets. Among
non chewers, 41.45% had no loss of attachment,
29.91% had 4-5 mm loss of attachment, 18.38% had
6-8 mm loss of attachment, 9.40% had 9-11 mm loss of
attachment and 0.85% had ≥ 12 mm loss of attachment.
Among chewers, 30.59% had calculus, 47.49% had
shallow pockets and 21.92% had deep pockets, 16.67%
had no loss of attachment, 28.79% had 4-5 mm loss
J. Nepal Dent. Assoc. (2009), Vol. 10, No.2
When smoking habits was correlated with different
variables, the following results were observed:
A correlation of chewing habits with smoking habits
revealed that 34.19% of non chewers and 21.21% of
chewers were non smokers. Relatively equal proportion
of non chewers (41.45%) and chewers (40.91%) were
light smokers. Among heavy smokers, 37.88% were
chewers and 24.36% were non chewers. (Table 3) (p
< 0.02).
100
Table 1: Periodontal status of the study population as per CPI score (%) according to different variables
Variables
(n)
CPI 0
CPI 1
CPI 2
CPI 3
CPI 4
Gender
Male
156
0
0
29.49
44.23
26.28
Female
144
0
0.69
45.83
39.58
13.89
118
0
0.85
50.85
34.75
13.56
Tooth powder and finger
49
0
0
36.73
42.86
20.41
Charcoal, sand, ash etc
133
0
0
25.56
48.12
26.32
Oral Hygiene Practices
Tooth brush and tooth paste
Smoking habit
Non smokers
94
0
1.06
57.45
34.04
7.45
Light smokers
124
0
0
29.03
50
20.97
82
0
0
26.83
39.02
34.15
234
0
0.43
39.74
38.89
20.94
66
0
0
28.79
53.03
18.18
77
0
1.3
58.44
25.97
14.29
Fair(1-1.9)
219
0
0
30.59
47.49
21.92
Poor (2-3)
4
0
0
0
50
50
(≤10 sticks/day)
Heavy smokers
(>10 sticks /day)
Chewing habits
Non chewers
Chewres
Plaque score
(Sillness and Loe)
Good(0-0.9)
Table 2: Periodontal status of the study population as per LOA score (%) according to different variables
Variables
(n)
LOA 0
LOA 1
LOA 2
LOA 3
LOA 4
Gender
Male
156
30.77
32.05
17.95
12.82
6.41
Female
144
41.67
27.08
21.53
9.72
0
118
55.93
22.88
46.61
5.93
2.54
Oral Hygiene Practices
Tooth brush and tooth paste
Tooth powder and finger
49
32.65
40.82
18.37
8.16
0
Charcoal, sand, ash etc
133
19.55
31.58
26.32
17.56
5.26
Non smokers
94
56.38
14.89
23.4
5.32
0
Light smokers
124
25
37.9
20.16
13.71
3.23
82
29.27
34.15
14.63
14.63
7.32
234
41.45
29.91
18.38
9.4
0.85
66
28.79
28.79
24.24
18.18
0
Smoking habit
(≤10 sticks/day)
Heavy smokers
(>10 sticks /day)
Chewing habits
Non chewers
Chewers
Plaque score
(Sillness and Loe)
Good(0-0.9)
77
55.84
19.48
14.29
6.49
3.9
Fair(1-1.9)
219
29.68
33.33
21.46
12.79
2.74
Poor (2-3)
4
0
25
25
25
25
101
J. Nepal Dent. Assoc. (2009), Vol. 10, No.2
Table 3: Relationship between various demographic factors in percentage (%)
Smoking
Plaque score
Oral hygiene
Tooth
Others
powder
12.77
30.85
good
Fair
poor
Non smoker
44.68
54.26
1.06
Tooth
brush
56.38
Light smoker
20.16
77.42
2.42
37.10
16.94
45.97
Heavy smoker
12.20
87.80
0
23.17
19.51
57.32
Oral hygiene
Plaque score
good
Tooth brush
Tooth powder
Others (charcoal, sand, ash)
fair
41.45
40.91
24.36
37.88
Chewing habits
poor
Non chewers
Chewers
71.43
28.31
25
39.74
37.88
6.49
20.09
0
11.97
31.82
22.08
51.60
75
48.29
30.30
Discussion
The age 35-44 years is a key age group acknowledged
by the WHO because, in most populations, all signs
of periodontal disease can be observed and various
stages of periodontal disease can be investigated,
though tooth loss is still not a phenomenon frequently
encountered3,22,23,24.
followed by light smokers and least in non smokers. This
finding demonstrates the detrimental effect tobacco has
on the periodontal tissues, which is in accordance with
other studies27, 29, 32. Various factors such as altered host
response33,34, changes in oral microflora35 may probably
contribute to more severe forms of periodontal disease
in smokers. Although the mechanisms by which tobacco
exerts its influences are not clearly known, it seems
likely that it primarily has a systemic influence affecting
host response or susceptibility27 .The results suggest
that smoking influences the prevalence and severity of
periodontal diseases and thus favour the hypothesis
that it is a major risk factor for periodontal disease. The
habit of tobacco and betel nut chewing was also shown
to adversely affect the health of the periodontal tissues
of the subjects. This finding is in agreement with earlier
reports36, 37, 38.
About 90% of the Nepalese population live in rural areas
with neither facility for any preventive nor therapeutic
dental services. Jhor Mahankal village, in Kathmandu
valley is one such village. A lack of reliable data on
prevalence of periodontal status in Nepal prompted
the survey. In the present study, the prevalence of
periodontal disease was found to be 100% in the
subjects, i.e., none of the subjects had a completely
healthy periodontium (Code 0) as their highest CPI
score. This is in comparison to other studies5, 25. Lack
of proper dental health knowledge and awareness and
the virtual absence of preventive and therapeutic dental
services could be the factors responsible for this rather
alarming state of unhealthy amongst this backward,
rural community. Calculus (Code 2) and shallow
pocketing (Code 3) were the most frequently observed
conditions. Thus this rural population exhibited a high
level of periodontal disease as was evident from the
prevalence of periodontal pockets which is in agreement
with several earlier studies24,26.
Prevalence of gingival recession was observed to be
more in subjects with chewing habits than non chewers
in the present study. Gingival recession and advanced
periodontal destruction have been reported adjacent
to the regions where the tobacco quid is held36, 37.This
greater severity of gingival recession observed in the
present study could probably be the result of mechanical
injury to the gingiva. Holm G38 has shown that increased
prevalence of gingival recession could be attributed
not only to mechanical but chemical irritating effect of
smokeless tobacco components. According to him, this
stimulus is likely to result in the release of inflammatory
mediators, toxic substances such as nitrosoamines
which may play a role in the development of periodontal
attachment loss and gingival recession. These
observations lend credence to the view that control of
such deleterious habits could pave the way to a great
extent in promoting periodontal health.
The detrimental effect of tobacco smoking on the
periodontal tissue was demonstrated in this study,
corroborating earlier reports27,28,29,30,31.The estimated
risk of periodontal destruction for smokers increased,
compared to the non smokers. Non smokers in general
had less periodontal destruction than smokers. This
value is comparable to those obtained by Goultschin28.
The percentage of subjects with deep pockets (Code 4)
were observed to be more in heavy cigarette smokers,
J. Nepal Dent. Assoc. (2009), Vol. 10, No.2
Chewing habits
Non
chewers
chewers
34.19
21.21
102
The various oral hygiene practices employed by this
rural population included the use of toothbrush and
tooth paste, tooth powder and others like charcoal, ash
and sand. It was observed that majority of subjects used
other methods. The tooth brush users were found to
have better periodontal health when compared to tooth
powder and other method users. This is in agreement
with other studies32,39,40. Greene JC40 noticed both in
urban and rural samples in India that tooth brush users
had lower periodontal disease scores than those who
used the finger as a means of cleaning the teeth, while
Ramfjord32, in an attempt to compare methods of oral
hygiene with the periodontal scores, showed that the
use of a brush was associated with a lower periodontal
disease score than other methods of oral hygiene. This
reinforces the belief that to date, the most dependable
mode of plaque control is mechanical cleaning with a
tooth brush.
Conclusion
In conclusion, we estimated the overall prevalence of
severe periodontal disease (6 mm or deeper periodontal
pockets) in subjects 35 -44 years of age to be 20.33%
using CPI and loss of attachment >3 mm to be 64%
using LOA, in a 300 study population of Jhor Mahankal
village. Data analysis revealed that this community which
is deprived of professional dental services or any oral
health education programmes had a high prevalence of
periodontal diseases. In light of these observations from
the present study the following recommendations for a
community based oral health programme suited to such
a population group may be made. The public needs
to be educated and motivated towards prevention of
periodontal diseases during childhood. This goal can be
pursued by laying adequate emphasis on school dental
health education programmes. A proper strategy thus
needs to be adopted in Nepal to promote and maintain
oral health through a well designed health care delivery
system. Such a scheme has already been introduced
in Chiang Mai, Thailand with remarkable success. To
contend with the oral health problems in Nepal, National
Oral Health Policy that emphasizes prevention will be
more advantageous and cheaper than the establishment
of traditional curative programmes. This survey was
confined to just one of the numerous villages of this
nation. More such surveys need to be conducted in
different parts of Nepal amongst populations with
different cultures, living conditions and habits. This
should enable us to devise and implement a National
Oral Health Programme best suited to this country.
In the present study, statistically significant higher plaque
scores were observed in smokers. This is comparable
with earlier report18. It could be attributed to the devices
used by higher percentages of smokers for cleaning
their teeth as most of the smokers used other devices
than tooth brush to clean their teeth. Majority of nonsmokers used tooth brush to clean their teeth (Table 3)
Plaque scores in chewers and non chewers were found
to be relatively similar.
Results of this study indicate a high prevalence of
plaque, calculus and shallow pockets among the
population examined, which shows that effectiveness
of the oral hygiene methods employed amongst them
is not very high and further, that the low number of
dental professionals in Nepal are unable to treat these
conditions adequately.
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more representative of the disease distribution within
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detect pathogenic bacteria or actively deteriorating
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into CPI should be explored to better detect and assess
destructive periodontal diseases.
103
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104
Journal of Nepal Dental Association (2009), Vol. 10, No. 2, Jul.-Dec., 105-109
Original Article
Spectrophotometric analysis of shade duplication of various
recent ceramic system used for porcelain fused to a metal
crown: An invitro study
Das DK 1, Dong CX2, Singh SK3, Roy J4
Resident, Dalian Medical University, China, 2Professor, Dalian Stomatological Hospital, China, 3Associate Professor, 4Dental Surgeon,
UCMS, Bhairahwa, Nepal.
1
Abstract
Objective: To evaluate and compare the colour difference of the total colour replication process and the direction
of the individual color parameters for dental porcelain of three brands.
Materials and methods: The fabricated shades (A2) of 3 different porcelain companies were determined visually
and instrumentally using Vita Lumin Shade Tab (A2) and Spectrophotometer. Corresponding porcelain disks were
made of approximately 0.8 mm metal, 0.2mm opaque, 0.8 mm dentin, 0.5mm enamel and glaze were fabricated
with each of the three porcelain brands (Vita VMK 95, Ceramco 3, Ceramax). The colour of the fabricated disks and
master disks were measured with a spectroradiometer with a 450/00 using {C.I.E 1931(xyz)} parameter. Analysis
of variance (ANOVA) was applied to evaluate within group differences among the porcelain groups for total colour
difference (D.E) and direction of colour parameters (D.L, D.RG, D.YB).
Result: The largest mean (D.E) was recorded for Ceramax and least for Vita VMK 95.A significant difference
(P= 0.015) was found in yellow and blue axis (D.YB). Data collected further showed no significant difference
between shade selection methods and the evaluated clinical criteria. The amount of change within each colour
parameters was dependent on the porcelain system, as well as the amount of change among colour parameters.
Conclusion: Samples made with different brands of porcelains have noticeably different shade despite having
the same Vita Lumin Shade Guide. Different brands of porcelain differ from each other more in redness and
yellowness. Different brands of porcelain differ from each other more in lighter than darker shades.
Key words: Spectrophotometer, Vita shade guide, Porcelain systems
Introduction
Colour matching between natural teeth, shade guides
and metal ceramic restorations is a common clinical
problem1.Use of shade guides is highly subjective2,
most existing commercial shade guides do no represent
the entire spectrum of tooth colour3.Due to inter human
difference in the perception of colour, visual shade
assessment of human teeth is lacking standardization that
may be improved by use of spectrophotometer4.General
variable such as external light conditions, experience,
age, fatigue of human eye and physiological variables
such as colour blindness lead to inconsistencies4.
Computerized shade matching system offers better
accuracy, improved efficiency and esthetic benefits to
the patient, dentist and technician. It analyzes the color
of natural tooth and calculate the exact rates of hue,
chroma and value for multitude of points on the tooth
surface and display this information on the computer
screen2.
Materials and methods
The materials used in this study were - Porcelain
systems: 1: Ceramco 3 (Dentsply International, USA,
code C) 2: Ceramax (Alphadent Co. Ltd, Korea, code
CM) 3: Vita VMK 95 (Vita Zahnfabrik H. Rauter GmbH
& Co.KG. Germany, code V) -Base Metal Alloy: Ni-Cr
alloy: (Brand-Ugirex, France, code N)
Correspondence
Dr. Dilip Kumar Das, Dalian Medical University, China
E-mail: [email protected]
105
J. Nepal Dent. Assoc. (2009), Vol. 10, No.2
For this study, the instrument geometry used was 450/00
with specular component excluded, as this geometry
closely relates to the normal human vision when
observing a natural tooth.
In this study 15 substructure patterns were fabricated
using inlay wax, then cut into 1 x 1 cm square pieces,
measured with digital Vernier caliper, followed by
casting with Ni-Cr alloy. Thickness of each specimen
was measured at nine locations having average mean
thickness of 0.8 mm approximately. The surface of
alloy in which porcelain was to be fired was air abraded
with 50μm aluminum oxide at 75psi pressure. All the
specimens were cleaned with pressurized steam for any
surface contaminants. The specimens were held under
vacuum for 2 minutes at 9600 C with temperature increase
of 700 C per minute according to the manufacturer
instructions.
Results
Presented below is the comparative analysis of the
respective mean values corresponding to each of the
three brands viz. V (Vita VMK 95), C (Ceramco 3) &
Cm (Ceramax); for each of the four parameters of
C.I.E1931(xyz)(International commission on Illumination)
i.e. D.E (Total colour difference), D.L (Sample darker
and lighter shades), D. RG. (Sample red and green) &
D.YB (Sample yellow and blue).
Each type of porcelain was applied on 5 samples each
(5 each of Ni-Cr).Wash opaque was applied as thin
layer with brush and fired. Each company shade had
its own opaque paste which was applied in thin layer
and then fired. Opaque thickness was determined with
a micrometer by measuring the sample at 3 points on
each disk. Dentine porcelain was mixed to a creamy
consistency using distilled water, vibrated mechanically
for proper condensation and fired. Final thickness of
1.8 mm approximately was ground to matte finish and
steam cleaned for removal of any surface contaminants.
Enamel powder was mixed on the glass slab with
a special liquid provided by the manufacturer into a
creamy consistency, spread evenly and over build to
compensate for the firing shrinkage and then fired. The
specimens were ground to approximate thickness of
0.5 mm of enamel porcelain. A thin layer of glaze was
applied and fired. All the five layers were fired by strictly
following the manufacturer’s instructions.
Table 1 shows that the highest mean value (17.98)
is recorded in case of brand Cm (Ceramax) & lowest
(16.15) in case of brand V (Vita VMK 95).
Table 2 shows that the value of F is not significant at
5 percent level of significance. Three brands may be
regarded as one and the same.
Table 3 shows that the highest mean value (14.25)
is recorded in case of brand V (VitaVMK95) & lowest
(13.24) in case of brand Cm (Ceramax).
Table 4 shows that the value of F is not significant at
5 percent level of significance. Three brands may be
regarded as one and the same.
Table 5 shows that the highest mean value (8.77) is
recorded in case of brand Cm (Ceramax) & lowest (6.43)
in case of brand V (Vita VMK 95).
Sample measurements and data manipulation
The samples were individually analyzed with Vita lumin
shade guide (A2) in a spectrolinao spectrophotometer. CIE
standard illuminant D65 was used for all measurements.
The colour of each sample in this study were described
by 4 parameters of C.I.E (International Commission on
Illumination) 1931(xyz). The resultant tristimulus values
X, Y, Z are the standard response of the eye to the red,
green, and blue stimuli from the object. The X (D.L)
parameter defines the lightness or darkness of samples
and its numerical value ranges from black (-) to white
(+). Similarly the other two axis defines (D.R.G) Red(+)
& Green(-) and (D.Y.B) Yellow(+) & blue(-). Evaluation
of color differences or DE in dental research is usually
performed with the following formula.
Table 6 shows that the value of F is not significant at
5 percent level of significance. Three brands may be
regarded as one and the same.
Table 7 shows that the highest mean value (6.72) is
recorded in case of brand Cm (Ceramax) & lowest (2.98)
in case of brand C (Ceramco 3).
Statistical Significance for difference in mean value has
been tested by Analysis of Variance (ANOVA) through
Table 8.
D.E = Dl2 + D.RG2 + D.YB2
Table 8 shows that the value of F is significant at 5 percent
level of significance. Three different brands cannot be
regarded as one and same since these are resulting
to mean values whose differences are significant at 5
percent level of significance.
The CIE system of color specification provides a common
means of analyzing and presenting color measurements
data.
As the difference between various brands has been found
to be statistically significant; the individual comparisons
between them are present in Table 9.
J. Nepal Dent. Assoc. (2009), Vol. 10, No.2
106
significantly from V and also C, at 5 percent level of
significance.
Table 9 shows that the difference between means
of brands V (Vita VMK 95) and C (Ceramco 3) is not
significant; while that of brand Cm (Ceramax) differs
D.E: Table 1: Mean Values
Replication
Brand
V
I
15.64
II
III
IV
14.81
15.70
18.07
V
16.54
Total
Mean
S. D
C.V
(In %)
80.76
16.15
1.24
7.68
C
18.48
19.20
19.12
15.56
10.44
82.80
16.56
3.73
22.52
Cm
18.72
17.79
18.31
14.38
20.72
89.92
17.98
2.30
12.79
Total
52.84
51.80
53.13
48.01
47.70
253.48
16.90
-
-
Table 2: ANOVA (D.E)
Between Groups
9.225
2
4.612
0.667
F tab
5%
3.88
Within Groups
83.004
12
6.917
-
-
-
Total
92.229
14
-
-
-
-
Sum of
squares
Source
Df
Mean square
F
P value
> 0.05
D.E: Table 3: Mean Values
V
I
13.49
II
14.16
Replication
III
14.36
IV
15.64
Brand
V
13.64
Total
Mean
S. D
C.V
(In %)
71.29
14.25
0.85
5.96
C
17.15
13.98
18.18
13.78
7.75
70.84
14.16
4.07
28.74
Cm
15.26
14.37
16.86
4.14
15.61
66.24
13.24
5.17
13.04
Total
45.90
42.51
49.40
33.56
37.00
208.37
13.89
-
-
Table 4: ANOVA (D.L)
3.114
2
1.557
.106
F tab
5%
3.88
Within Groups
176.174
12
14.681
-
-
-
Total
179.288
14
-
-
-
-
Source
Sum of Squares
Between Groups
Df
Mean
Square
F
P value
> 0.05
D.RG: Table 5: Mean Values
V
I
7.38
II
4.06
Replication
III
6.00
Brand
IV
5.66
V
9.07
Total
Mean
S. D
C.V
(In %)
32.17
6.43
1.90
29.55
C
6.14
12.05
5.74
6.90
6.39
37.22
7.44
2.61
35.08
Cm
7.90
9.62
4.76
11.57
10.00
43.85
8.77
1.41
16.08
Total
52.84
51.80
53.13
48.01
47.70
253.48
16.90
-
-
Table 6: ANOVA (D.RG)
Source
F tab
P value
Sum of squares
Df
Mean square
F
Between Groups
13.721
2
6.861
1.203
3.88
> 0.05
Within Groups
68.422
12
5.702
-
-
-
Total
82.143
14
-
-
-
-
107
5%
J. Nepal Dent. Assoc. (2009), Vol. 10, No.2
D.YB: Table 7: Mean Values
Replication
Brand
I
Ii
Iii
Iv
V
Total
Mean
C.V
(In %)
S. D.
V
2.88
1.50
2.05
7.07
2.28
15.78
3.15
2.24
71.11
C
3.08
5.29
1.58
2.18
2.81
14.94
2.98
1.41
47.32
Cm
7.42
4.13
5.32
7.48
9.25
33.60
6.72
2.00
29.76
Total
13.38
10.92
8.95
16.73
14.34
64.32
4.29
-
-
Table 8: ANOVA (D.YB)
Source
Sum of squares
Between Groups
Within Groups
Total
F tab
P value
Df
Mean square
F
44.380
2
22.190
6.018*
3.88
< 0.05
44.248
12
3.687
-
-
-
88.628
14
-
-
-
-
5%
*: Significant at 5 percent level of significance
Table 9: Summary Table
Brand
V
C
Cm
C. D (critical
difference)
Mean
3.15
2.98
6.72
1.21
Discussion
The most important goal in modern dentistry is to restore
colour and appearance of natural dentition5. Due to
superior optical properties, ceramics have become a
standard application as a dental restorative material
to mimic natural tooth esthetics6. A large number of
studies have shown the variation in shade due to the
type of metal alloy7,8, shade selected9,10, brand and
batch of porcelain11, firing temperature and number of
firings12, as well as thickness of the porcelain layer13,14.
Minimizing one or more of these errors will overall help
in duplication of more acceptable shades for the patient.
In such scenario, instrumental color analysis offers
potential advantages over visual color determination.
Vita lumin shade guide is the most widely used standard
for shade selection in dentistry worldwide in spite of its
many drawbacks2, 15.
The particle size of the porcelain is known to affect the
perceived colour by affecting the scattering property, as
small particles scatter less light than big particles. These
2 properties, the smooth surface topography and the
small particle size, are thought to be responsible for the
better colour quality and reproducibility.
One of the objectives of this study was to evaluate the
shade difference when A2 shades of 3 different brands of
porcelain were fired on the same metal. This difference
is due to the different concentration of shade pigments
used by the manufacturers. The 3 porcelain brands
differed significantly from each other mostly in their
amount of yellow saturation. In our study observation
of Chroma of all three samples (Ceramco 3, Ceramax
and VitaVMK 95) was statistically insignificant in terms
D.RG (Red and Green). Batch to batch variation of
porcelain may necessitate the fabrication of customized
shade tabs with fresh batch of porcelain11,17. In our study,
observation of Chroma of all three samples (Ceramco
3, Ceramax and Vita VMK 95) varied and significant
in terms of D.YB (yellow and blue) where as in other
studies, the yellowness increased with thickness and
shade of opaque. Their observation showed difference
(0.05) due to difference in thickness in porcelain and also
due to different types of condensation techniques16,18.
Also difference in D.L lightness (value) has been seen
between 3 samples of experimental group of porcelain
and was statistically insignificant. In our study D.E
The specimens were made manually and there is bound
to be difference within an experimental group, which
contained five samples, each fired on the same metal
with different brand of porcelain. This error is mostly due
to difference in condensation of the porcelain as any air
bubbles incorporated usually influences the shade16.
The Vita VMK 95 experimental group samples presented
the minimum deviation in D.E, D.L among all the groups
i.e. it was least technique sensitive. The Ceramco
3 experimental group samples presented minimum
deviation in D.YB and Ceramax experimental samples
group presented minimum deviations in D.RG group.
J. Nepal Dent. Assoc. (2009), Vol. 10, No.2
108
(difference) in all three samples (Vita VMK 95, Ceramax,
Ceramco3) were subjectly observed and statistically
insignificant. The experimental group which came
closest to the shade tab was VitaVMK 95 samples, as
the saturation of the colouring oxides are under the
control of the same manufacturer both in shade guide
and porcelain powder3.The largest error was seen with
Ceramax. The operator using porcelain should posse
sufficient knowledge so that the best judgment can
be exercised in the selection of physical and chemical
property of different types of material.
Conclusions
7.
Hammad IA, Stein RS. The qualitative study for the bond
and color of ceramometals, Part. II. J Prosthet Dent 1991;
65:169.-79.
8.
Groh CL, O’Brien WJ, Boenke KM. Differences in
color between fired porcelain and shade guides. Int J
Prosthodont 1992;5:510-4.
9.
Seghi RR, Johnston WM, O’Brien WS. Spectrophotometric
analysis of color differences between porcelain systems.
J Prosthet Dent 1986;56:35-40.
10.
Bolt RA, Bosch JJ, Coops JC. Influence of window size in
small-window colour measurement, particularly of teeth.
Phys Med Biol 1994;39:1133-42.
11.
Jorgenson MW, Goodkind RJ. Spectrophotometric study
of five porcelain shades relative to the dimensions of color,
porcelain thickness, and repeated firings. J Prosthet Dent
1979; 42:96-105.
12.
Rade P, Dragutin S, Ljiljana A et al. Problems in standard
shade matching and reproduction procedure in dentistry,
A review of the state of the art. The scientific journal Facta
Universitatis 1997; 4(1):12-16.
13.
Barghi N, Lorenzana RE. Optimum thickness of opaque
and body porcelain. J Prosthet Dent. 1982; 48:429-31.
14.
Evans DB, Barghi N, Malloy CM, Windeler AS. The
influence of condensation method on porosity and shade
of body porcelain. J Prosthet Dent 1990;63:380-9.
15.
Paul S, Peter A, Pietrobon N, Hammerle CH. Visual and
spectrophotometric shade analysis of human teeth. J
Dent Res 2002;81: 578-82.
16.
Carlson GE, Wagner IV, Odman P et al. An international
comparative multicenter study of assessment of dental
appearance using computer-aided image manipulation.
Int J Prosthodont 1998; 11:246-54.
17.
Goetzen N, Gerd N, Michael MM et al. Analysis of all
ceramic fixed partial dentures. Summer Bioengineering
Conference; Sonesta Beach Resort in Key Biscayne,
Florida 2003; June 25-29.
18.
Dozic A, Kleverlaan CJ, Meegdes M, Van der Zel J,
Feilzer AJ. The influence of porcelain layer thickness on
the final shade of ceramic restorations. J Prosthet Dent
2003;90:563-70.
1. Samples made with different brands of porcelains
have noticeably different shades despite having
same Vita Lumin shade guide.
2. Different brands of porcelain differ from each other
more in redness and yellowness.
3. Different brands of porcelain differ from each other
more in lighter than darker shades.
References
1.
2.
Kourtis SG, Tripodakis AP, Doukoudakis AA.
Spectrophotometric evaluation of optical influence of
different metal alloys and porcelain in the metal ceramic
complex. J Prosthet Dent 2004; 92:477-85.
Ishikawa-Nagai S, Ishibashi K,Tsuruta O, Weber HP.
Reproducibility of tooth color gradation using a computer
color-matching technique applied to ceramic restoration.
J Prosthet Dent 2005; 93: 129-37.
3.
Miller L. Organizing color in dentistry. J Am Dent Assoc
1987 Spec No: 26E-40E.
4.
Seghi RR, Johnston WM, O’Brien WJ. Performance
assessment of calorimetric devices on dental porcelain.
J Dent Res 1989;68:1755-9.
5.
Brewer JD, Akers CK, Garlapo DA, Sorensen SE.
Spectrometric analysis of the influence of metal substrates
on the color of metal-ceramic restorations. J Dent Res
1985 64:74-7.
6.
Crispin BJ, Seghi RR, Globe H. Effect of different
metal ceramic alloys on the color of opaque and dentin
porcelain. J Prosthet Dent 1991;65:351-6.
109
J. Nepal Dent. Assoc. (2009), Vol. 10, No.2
Journal of Nepal Dental Association (2009), Vol. 10, No. 2, Jul.-Dec., 110-114
Original Article
Dental arch length and arch symmetry analysis of Nepalese
permanent dentition
Shrestha RM1, Bhattarai P2
1
Consultant Orthodontist, Kathmandu Model Hospital, 2Consultant Orthodontist, The Orthodontic Center
Abstract
Objective: To study the dental arch lengths at canines and first molars of permanent dentitions of Nepalese adults
using Lavelle’s method.
Materials and methods: Dental stone models of one hundred subjects with normal occlusion and dentofacial
proportion were studied using standard Boley gauze. The study compared gender differences among the Nepalese
adults as well as between the Nepalese and Caucasian samples.
Results: Arch lengths of the Nepalese males were significantly greater than those of the females at all parameters
studied except at mandibular canine. The arch lengths of the Nepalese adults were significantly greater than those
of the Caucasians except at mandibular canine.
Conclusion: Significant variation between left and right sides of the dental arch lengths at mandibular canine
region suggest asymmetry of dental arch among Nepalese adults.
Key words: Arch length, Arch Symmetry, Lavelle’s method
Introduction
Lavelle1 in 1971 defined dental arch length as the
oblique dimension measured between the most
mesial aspect of anterior teeth and the most distal
aspects of posterior teeth. The dental arch length
denotes the sagittal dimension of the dental arch from
most anterior reference point to the posterior surface.
Various researchers have measured the dental arch
length differently; and many consider arch length and
arch depth synonymously. Other researchers including
Burris2, DeKock3, and Barrett4 measured arch length
at mid-palatal line. Sanin5 estimated dental arch length
using fourth degree polynomial formula.
The study on dental arch symmetry is of interest to
orthodontists from functional as well as esthetic point
of view. Historically Gruenburg11 in 1912 devised
“symmetroscope” to measure the symmetry of the
dental arch; later Friel12 modified it as a transparent
celluloid sheet with ruled squares. Lu13 in 1964 studied
the symmetry of dental arch using orthogonal polynomial
analysis. BeGole14 suggested cubic spline curve as an
ideal means to represent the asymmetry of the dental
arch. Comparing left and right sides of the dental arch
has been the most common method to describe the arch
asymmetry. Lavelle & Plant15 compared right and left
sides of the dental arch with normal occlusion to analyze
arch symmetry using traveling microscope.
Anthropologists believe that different racial types have
differently shaped dental arches. Williams6 in 1917 stated
that arches vary slightly to harmonize with different racial
types, and the variability within a racial type is extremely
less. Laine7 showed that, arch length did not differ from
one Caucasoid population group to another of same
age range. Buris2, Merz8 found that the Black subject's
arches were longer compared to Whites. Confirming the
general observation, most of the researchers including
Barrett4, Bishara9, and Huang10 found greater dimension
of arch length in males compared to females.
The racial, sexual and symmetrical variations in dental
arch lengths are thus deemed important to be analyzed
for permanent dentition of the Nepalese adults. The study
is believed to be useful for orthodontic, odontometric
and anthropometric purposes.
Materials and methods
The sample consisted of dental stone cast of one
hundred Nepalese adults aged 17 to 32 years; with
Correspondence
Dr. Rabindra Man Shrestha, Consultant Orthodontist, Kathmandu Model Hospital, Kathmandu
E-mail: [email protected]
J. Nepal Dent. Assoc. (2009), Vol. 10, No.2
110
equal female to male ratio. The sampling was based
on inclusion criteria established for the research.
The samples possessed all permanent teeth (with or
without third molars), Angle’s Class I molar and canine
relationships, normal overjet and overbite, orthognathic
skeletal and facial profile. The subjects were selected
among the patients who visited to the Dental Center of
Kathmandu Model Hospital and among the participants
of dental camp organized by the same center.
When comparing the arch lengths between Nepalese
females and males, all mean values of the males were
significantly greater than those of the females at all
dimensions except for the mandibular arch length at
canine on the left side (Table 4 and Table 5).
When comparing the difference between Nepalese
females and males for the average of right and left arch
lengths, all dimensions were greater in males except for
arch length at mandibular canine (Table 6).
The measurement of dental arch length followed the
method described by Lavelle et al1. The dimensions were
measured between the mesial line angles of the central
incisors to the distal contact point of the canine and to
the distal contact point of first molar in oblique direction
on both right and left sides (Fig 1). The measurements
were performed directly on maxillary and mandibular
casts using standard Boley gauge (Dentaurum Munchner
model) of 0.1 mm accuracy.
Table 7 shows that the mandibular arch length at canine
on left side is significantly greater than that on the right
side of the combined Nepalese females and males.
The study shows that all arch length measurements
except at the mandibular canine length were greater in
Nepalese compared to the Caucasian samples (Table
8). Table 9 illustrates the comparative arch lengths of
Nepalese adults with other racial groups as reported by
Lavelle.
The samples were analyzed for the statistical difference
between female and male sexes, and between the
Nepalese and Caucasian (British) samples. The mean
arch lengths were compared between right and left
sides to analyze the symmetry of the dental arch. The
data were also compared with Cucasians, Australian
aboriginies, Negroid and Mongoloid races as reported
by Lavelle1. The statistical analysis was performed using
Student’s t-test at the level of significance of 0.05.
Result
A descriptive statistics of the mean arch lengths of
Nepalese female, male, and combined female and male
subjects are presented in Table 1, Table 2, and Table 3
respectively. The data also show the average of the right
and left dimensions.
Fig 1: Dental arch length reference points
Table 1: Descriptive statistics for the arch lengths of Nepalese females (in mm)
Right
Mx
Md
Left
Average
Mean
SD
Range
Mean
SD
Range
Mean
SD
Range
I1 – C
22.17
1.02
4..80
22.10
1.07
5.30
22.14
1.04
5.05
I1 – M1
43.23
1.54
6.80
43.33
1.71
8.30
43.28
1.60
7.55
I1 – C
16.96
0.77
3.50
17.09
0.75
3.40
17.03
0.74
3.40
I1 – M1
39.00
1.52
7.80
39.11
1.47
7.30
39.05
1.47
7.55
Table 2: Descriptive statistics for the arch lengths of Nepalese males (in mm)
Right
Mx
Md
Left
Average
Mean
SD
Range
Mean
SD
Range
Mean
SD
Range
I1 – C
22.68
1.14
4.60
22.67
1.08
4.30
22.68
1.09
4.45
I1 – M1
44.41
1.98
8.80
44.33
1.92
8.30
44.37
1.93
8.50
I1 – C
17.31
0.92
3.60
17.40
0.91
4.00
17.36
0.90
3.70
I1 – M1
40.01
1.67
7.00
40.12
1.91
8.10
40.06
1.77
7.30
111
J. Nepal Dent. Assoc. (2009), Vol. 10, No.2
Table 3: Descriptive statistics for the arch lengths of combined Nepalese females and males (in mm)
Right
Mean
Mx
Md
SD
Left
Range
Mean
SD
Average
Range
Mean
SD
Range
I1 - C
22.43
1.11
5.70
22.39
1.11
5.50
22.41
1.09
5.60
I1 – M1
43.82
1.86
8.80
43.83
1.88
9.20
43.83
1.85
8.75
I1 - C
17.13
0.86
3.80
17.25
0.85
4.00
17.19
0.84
3.85
I1 – M1
39.50
1.67
7.80
39.61
1.77
9.00
39.56
1.70
8.05
Table 4: t-Test of significance for the difference between the mean arch lengths of Nepalese females and males on right
side
Female
Mx
Md
Male
p-value
Significance
Mean
S.D.
Mean
S.D.
I1 – C
22.17
1.02
22.68
1.14
0.021
*
I1 – M1
43.23
1.54
44.41
1.98
0.001
***
I1 – C
16.96
0.77
17.31
0.92
0.038
*
I1 – M1
39.00
1.52
40.01
1.67
0.002
**
(* P ≤ 0.05, ** P ≤ 0.01, *** P ≤ 0.001)
Table 5: t-Test of significance for the difference between the mean arch lengths of Nepalese females and males on left
side
Female
Mx
Md
Male
Mean
S.D.
Mean
S.D.
p-value
Significance
I1 – C
22.10
1.07
22.67
1.08
0.009
I1 – M1
43.33
1.71
44.33
1.92
0.007
**
I1 – C
17.09
0.75
17.40
0.91
0.066
NS
I1 – M1
39.11
1.47
40.12
1.91
0.004
**
**
(NS = not significant, ** P ≤ 0.01)
Table 6: t-Test of significance for the difference between the sexes for the average of right and left arch lengths
Female
Mean
Mx
Md
Male
S.D.
Mean
S.D.
p-value
Significance
I1 – C
22.14
1.04
22.68
1.09
0.012
*
I1 – M1
43.28
1.60
44.37
1.93
0.003
**
I1 – C
17.03
0.74
17.36
0.90
0.051
NS
I1 – M1
39.05
1.47
40.06
1.77
0.003
**
(NS = not significant, * P ≤ 0.05, ** P ≤ 0.01)
Table 7: t-Test of significance for the difference between right and left arch lengths of combined Nepalese females and
males
Right
Mean
Mx
Md
Left
S.D.
Mean
S.D.
p-value
Significance
I1 – C
22.43
1.11
22.39
1.11
0.361
NS
I1 – M1
43.82
1.86
43.83
1.88
0.879
NS
I1 – C
17.13
0.86
17.25
0.85
0.001
***
I1 – M1
39.50
1.67
39.61
1.77
0.062
NS
(NS = not significant, *** P ≤ 0.001)
J. Nepal Dent. Assoc. (2009), Vol. 10, No.2
112
Table 8: t-Test of significance for the difference between the arch lengths of Nepalese and Caucasian subjects
Caucasian
(Lavelle, 1971)
Mean
Mx
Md
Nepalese
(Shrestha, 2009)
S.D.
Mean
p-value
Significance
S.D.
I1 – C
17.7
1.16
22.41
1.09
0.000000
***
I1 – M1
36.9
0.82
43.83
1.85
0.000000
***
I1 – C
17.5
1.18
17.19
0.84
0.082809
NS
I1 – M1
38.5
0.29
39.56
1.70
0.000141
***
(NS = not significant, *** P ≤ 0.001)
Table 9: Comparative arch lengths of Nepalese and other racial groups
Caucasian
(Lavelle, 1971)
Mx
Md
I1 - C
Australian Aborigine
(Lavelle, 1971)
Negroid
(Lavelle, 1971)
Mongoloid
(Lavelle, 1971)
Nepalese
(Shrestha, 2009)
Mean
SD
Mean
SD
Mean
SD
Mean
SD
Mean
SD
17.7
1.16
18.6
1.12
22.7
0.58
18.2
0.56
22.4
1.09
I1 – M1
36.9
0.82
47.7
0.53
38.9
0.53
36.0
0.53
43.8
1.85
I1 - C
17.5
1.18
18.1
1.11
17.8
0.63
18.8
0.49
17.2
0.84
I1 – M1
38.5
0.29
38.8
0.57
38.4
1.13
39.0
0.47
39.6
1.70
Discussion
The odontometric or anthropometric study of dental
arch is best performed among adults. Proffit16 noted
a definitive sequence of jaw growth in three planes of
space. The growth of the dental arch width is completed
first, followed by arch length, and finally growth in arch
height takes place. DeKock,3 Sinclair,17 Bishara,18 and
Harris19 reported decrease in dimension of arch length
with the attainment of adulthood, then after the dental
arch attains the stable dimension.
observed the dimensions of the teeth and arch lengths
on right side were greater than those on the left, but the
differences were insignificant. Bishara, Jacobsen et al.18
however found no significant differences between right
and left sides in arch length measurement. The present
analysis showed that the mandibular arch length at
canine region was significantly greater on left side. The
apparent bilateral differences on arch dimensions show
that the Nepalese dental arch with normal occlusion is
dimensionally asymmetrical.
The present study is in agreement with the findings
of Barrett4, Bishara9, and Huang10 confirming that
arch lengths of the males were greater than those of
the females. The present study is also consistent with
the contemporary studies on arch width20 and arch
circumference21 of the Nepalese adults; which reported
that arch dimensions of the Nepalese males were
significantly greater as compared to females.
Kanazawa24 observed significant correlation between the
size of the teeth and length of the dental arch. However
present study is not consistent with such finding. The
present study found greater dimensions of arch length
on left side contrarily another study25 on mesio-distal
tooth diameter of Nepalese adults show most of the tooth
dimensions significantly wider on right side. Thus these
facts imply that the arch lengths are not dependent on
mesio-distal crown diameters.
The racial variation in arch length is also evident from the
present study. The arch lengths of the Nepalese adults
were significantly greater than those of the Caucasians
suggesting the longer dental arch sagitally. This finding
is consistent with the cephalometric study22 on Nepalese
adults which reported that both maxilla and mandible in
relation to cranial base were positioned more anteriorly
with greater SNA and SNB angles.
Conclusion
Most theories consider dental arch forms to be
symmetrical. White23 however observed a great deal
of asymmetry in the dental arches. Lavelle & Plant15
113
•
Dental arch lengths of Nepalese males are
significantly greater than those of the females for
both maxillary and mandibular canine and first molar
dimensions except at mandibular canine on left
side.
•
Average of the left and right arch lengths of the
Nepalese males are significantly greater than those
of the females for all dimensions except at mandibular
canine.
J. Nepal Dent. Assoc. (2009), Vol. 10, No.2
•
•
Mandibular arch length at canine on left side is
significantly greater than that on the right side of the
combined Nepalese adults suggesting asymmetry of
the dental arch at the region of mandibular canine.
All arch length measurements of the Nepalese
adults were significantly greater than those of the
Caucasians except at the mandibular canine.
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2.
Lavelle CL, Foster TD, Flinn RM. Dental arch in various
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Burris BG, Harris EF. Maxillary arch size and shape in
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Friel S. The diagnosis of malocclusion of the teeth. Dent
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Lu KH. An orthogonal analysis of the form, symmetry,
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Begole EA. A computer program for the analysis of
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Lavelle CLB, Plant CG. Comparison between the right and
left sides of the dental arch. J Dent Res 1969;48:971.
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Sinclair PM, Little RM. Maturation of untreated normal
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Barrett MJ, Brown T, Macdonald MR. Size of dental
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6.
Williams PN: Determining the shape of the normal arch.
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Shrestha RM, Bhattarai P. Dental arch circumference
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Bhattarai P. Steiner’s cephalometric analysis of Nepalese
adults aged 18 to 30 years. J Nep Dent Assoc 2005;7:19.
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White LW. Accurate arch discrepancy measurements. Am
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Merz ML, Isaacson RJ, Germane N, Rubenstein LK.
Tooth diameters and arch perimeters in a black and
a white population. Am J Orthod Dentofacial Orthop
1991;100:53-8.
9.
Bishara SE, Treder JE, Damon P, Olsen M. Changes in
the dental arches and dentition between 25 and 45 years
of age. Angle Orthod 1996;66:417-22.
24.
Kanazawa E, Sekikawa M, Ozaki T. Correlations between
the dimensions of human teeth, the dental arch and the
mandible. J Nihon Univ Sch Dent 1987;29:165-79.
10.
Huang ST, Miura F, Soma K.. A dental anthropological
study of Chinese in Taiwan (2). Teeth size, dental arch
dimensions and forms. Gaoxiong Yi Xue Ke Xue Za Zhi
1991;7:635-43.
25.
Shrestha RM. Measurement of mesio-distal tooth
diameter of Nepalese permanent dentition. J Nep Dent
Asso 2005;7:55-63.
11.
Gruenburg J. The symmetroscope: An apparatus for
measuring the symmetry or asymmetry of dental arches.
Dent Cosmos 1912;54:490-91.
J. Nepal Dent. Assoc. (2009), Vol. 10, No.2
114
Journal of Nepal Dental Association (2009), Vol. 10, No. 2, Jul.-Dec., 115-118
Original Article
Co-relation between the pattern of impaction of mandibular
third molars with their associated pathologies
Nyachhyon P1, Mahat A2
Assistant Professor, 2Demonstrator, Department of Oral & Maxillofacial Surgery, People’s Dental College & Hospital, Naya Bazar,
Kathmandu, Nepal
1
Abstract
Objective: The purpose of this study was to assess the pathologies associated with the different patterns of
impacted mandibular third molars and significance of its prophylactic removal.
Study Design: A descriptive non-randomized case series study was carried out in a total of two hundred patients
presenting with mandibular 3rd molar impactions in the Department of Oral and Maxillofacial Surgery, People's
Dental College & Hospital.
Result: Pericoronitis (31%) was mainly seen in patients below 30 yrs and associated commonly with vertical
impaction whereas dental caries in adjacent 2nd molar was seen in older patients and with mesioangular impaction.
Anterior teeth crowding was observed mainly with mesioangular impaction(43%). Cysts (3%) and tumor (<1%)
were least common findings associated with impacted third molar.
Conclusion: The presence of disease associated with third molar teeth is an indication for their removal but
‘prophylactic’ removal remains controversial. It is not mandatory to remove lower wisdom tooth simply because
they are impacted. Each case is considered individually to balance the benefits and risks of both retention and
extraction and to plan the treatment accordingly.
Key words: Impacted third molar, Pericoronitis, Prophylactic removal
Prophylactic removal vs. Non-Extraction
Debates exist whether to remove the impacted molars
before they become symptomatic. Advocacy for
prophylactic removal are based on to avoid the possible
pathologies and to facilitate early healing. Impacted
third molar can lead to diverse pathologies3 and have
been implicated in infections, periodontal problems,
resorption of 2nd molars, cysts and tumors of mandible4,
lower arch crowding, TMJ disorders and neuralgias5.
Removal of the impacted lower third molars has also
shown to reduce the incidence of fracture at the angle
of mandible4. Whereas retaining the tooth, patients will
avoid undue surgical discomfort, prolonged recovery
time, increased expense as well as damage to the
adjacent vital structures and bony support3.
Introduction
Impacted wisdom tooth is a common finding in general
dental practice and the removal of the third molars in
young adults is the common surgical intervention.
Incidence of impacted third molars is more common
in the mandible (90%) than the maxilla and the rising
number of incidence of the impacted tooth is making it
a public health problem1. However controversy persists
with respect to the associated pathologies and the
need for removal of the impacted wisdom tooth. The
proportion of third molars that are removed when no
disease is present is reported to be between 18% and
40%2. Prophylactic third molar surgery is based on the
concept of minimizing the future risk of disease and
surgical morbidity in older patients. Risk benefit ratio
and socio-economical considerations need to be taken
into account before a decision is made to remove the
impacted third molar, and if extraction has been decided
as the treatment option, one should know why, when
and how.
Study design
A descriptive study was carried out in a total of two
hundred patients presenting with mandibular 3rd molar
impactions in the Department of Oral and Maxillofacial
Correspondence
Dr. Pawan Nyachhyon, Assistant Professor, Department of Oral & Maxillofacial Surgery, People’s Dental College & Hospital, Naya Bazar,
Kathmandu, Nepal, E-mail: [email protected]
115
J. Nepal Dent. Assoc. (2009), Vol. 10, No.2
Surgery, People's Dental College & Hospital. The
selection criterion was non-randomized including all
cases of mandibular 3rd molar impactions (irrelevant of
age and sex) presenting in the department.
dental caries was more frequent in older patients. Among
the impactions, mesioangular impactions (42%) were
more common followed by horizontal (26%), vertical
(24%) and distoangular impactions (8%) (Fig 5).
The exclusion criteria for the study were cases in which
the adjacent second molars were absent, the patients
requiring full mouth extractions including mandibular 3rd
molar due to other reasons and patients who were not
willing for extraction.
Pericoronitis (31%) was the most commonly seen
pathology followed by other periodontal problems (12%)
and dental caries in the adjacent second molar (12%).
Facial infections like cellulites and osteomylites were
less common (4%) (Fig 6).
A standard history and clinical examination was carried
out in all patients and an Intraoral periapical radiograph
and/or Orthopantomogram were made as investigations.
A specially designed proforma was filled and the
location, angulation, depth, relationship to ramus and
the associated pathologies were noted. All the data
collected was entered in SPSS version 10 and results
were analyzed accordingly.
Pericoronitis (Fig 7) was the most commonly associated
pathology in 80% of vertical, 60% of horizontal, 52% of
distoangular and 23% of mesioangular impactions (Fig
8).
Lower anterior crowding was associated with 43% of
mesioangular, 18% of distoangular, 15% of horizontal
and 5% of vertical impactions (Fig 8). Most patients
below 20 years old underwent surgical extraction of the
impacted tooth for orthodontic purpose.
Results
There was more or less equal distribution of male (49%)
and female (51%) patients (Fig 1). Unilateral (49%) and
bilateral (51%) impactions were almost equally distributed
(Fig 2). Impacted third molars were more common on the
right side of the mandible (58%) (Fig 3).
Caries in the adjacent second molar (Fig 9) was seen in
22% of mesioangular and 15% of horizontal impactions;
and no carious lesions were seen in vertical and
distoangular impactions.
Dentigerous cysts (Fig 10) and odontogenic
keratocyst were found in 3% of the patients and tumor
(ameloblastoma) (Fig 11) was evident in 1% of all the
impacted mandibular third molars.
23% of the patients were less than 20 years old, 59%
of the patients were aged between 21-30 years, 13%
patients were between 31-40 years old and only 5%
were more than 40 years old (Fig 4). Pericoronitis was
more common in the younger age group (< 30 yrs) while
Left
42%
Female
Male
49%
51%
Right
58%
Fig 3: Location of impacted teeth
Fig 1: Distribution of male and female patients
31-40 yrs
13%
Unilateral
49%
>40 yrs
5%
Bilateral
51%
21-30 yrs
59%
Fig 2: Distributio of location of impacted third molar
(Unilateral vs. Bilateral)
J. Nepal Dent. Assoc. (2009), Vol. 10, No.2
Fig 4: Distribution of age groups
116
<20 yrs
23%
40%
35%
30%
25%
20%
10%
5%
0%
mesioangular vertical
25%
12%
12%
6%
4%
4%
pe
pe
ric
rio
or
on
do
it i
nt
s
al
po
ck
ca
et
rie
s
ad
s/
jt
p
ul
oo
pi
th
tis
/ro
ot
an
ca
te
r ie
r io
s
rc
ad
r
ow
jr
oo
di
fa
ng
tr
sc
es
ia
or
ls
pt
pa
io
ce
n
in
fe
ct
io
n
15%
31%
horizontal distoangular
Fig 5: Distribution of types of impactions
6%
ot
he
rs
35%
30%
25%
20%
15%
10%
5%
0%
45%
Fig 6: Distribution of associated pathologies
8
80
7
70
mesioangular
6
60
horiz
zontal
5
50
vertical
4
40
disto
oangular
3
30
2
20
10
0
perio/p
pericoronitis
Fig 7: Pericoronits
ant. crowd
ding
caries/pulpitis
adj. tootth caries
others
Fig 8: Common associated pathologies of the patterns of impaction
Fig 9: Caries in distal of adjacent 2nd molar Fig 10: Dentigerous cyst Fig 11: Ameloblastoma
100%
90%
80%
70%
60%
<20
50%
21-30
40%
31-40
30%
20%
40+
10%
0%
perio/infection
anterior
crowding
adj tooth/root
caries
cysts
ameloblastoma
Fig 12: Common causes of extraction in different age groups
117
J. Nepal Dent. Assoc. (2009), Vol. 10, No.2
Discussion
Our study showed more or less equal incidence of
unilateral and bilateral impactions of mandibular third
molars also almost equal distribution between both
sexes. However, the right mandibular wisdom tooth was
more frequently impacted than the left. Mesioangular
impaction (42%) was the most common pattern of
impaction while distoangular impaction (8%) was the
least common.
removal of impacted third molar teeth for prevention
of disease. Since the incidence of serious pathologies
is not very common, it is not mandatory to remove
impacted lower wisdom tooth simply because they are
present. The symptoms suffered by the patients, signs
noted by the clinicians and the risk of future problem
must outweigh the potential morbidity of the surgical
extraction procedure. The patient must be in possession
of sufficient information to make his decision. In a
patient with good oral hygiene, a wait and see policy
with regards to impacted 3rd molar is prudent than
prophylactic removal.
A majority of the patients presenting with impacted lower
third molar were aged between 20-30 years while 5% of
the patients were more than 40 years old. Pericoronitis
has been widely reported as the main reason for
extraction of lower third molars6. In our study, most of
the young patients underwent extraction for orthodontic
purpose and due to repeated pericoronitis (31%) while
dental caries (12%) was most common in the older
group. Several authors have suggested that there is a
close correlation between the risk of acute disease and
the angulation and degree of impaction of third molars7.
Our findings are in conformity with their studies.
Recommendation
It is recommended to consider each case individually,
to balance the benefits and risks of both retention
and extraction and to plan the treatment accordingly.
Whenever the non-extraction strategy is adopted,
long-term clinical and radiographic checks should
be maintained, so that surgical intervention can be
instituted as soon as pathology starts to develop.
Facial infections like cellulites and osteomylites were
found to be less common (4%) and the occurrence of
more serious pathologies like cysts (3%) and tumors
(1%) were low in our study., A number of studies
have supported the role of 3 rd molars in crowding
of the lower arch 8. 25% of impacted third molars
were extracted for orthodontic purposes to relief
anterior crowding.
References
In Obiechina’s study3, 57.51 % of impacted teeth were
associated with pathology. Out of these, 42.9 % were
cases of pericoronitis and periodontal disease, 13.9 %
were carious and 0.63 % were associated with cysts. In
a study conducted by Guven4 on 9994 impacted third
molars, 3.10 % were associated with some sort of cyst
(2.31%) or tumour (0.79 %). Out of these cases, 68 %
of the cysts were in mandible, out of these 93 % were
cases of dentigerous cysts and 7 % of odontogenic
keratocysts. The presence of tumours in mandibular
impacted third molars were 92 % of the total number
of tumours associated with impacted molars. Bruce
reported an incidence of 6.2% of cysts and tumours
developing around impacted mandibular third molars
and the incidence was notably highest (13.3 %) in the
oldest age group (mean age 46.5 years)9.
Conclusion
Although there is general agreement by dentists and
oral surgeons that the presence of disease associated
with third molar teeth is an indication for their removal,
‘prophylactic’ removal remains controversial. There
is currently little scientific evidence to support routine
J. Nepal Dent. Assoc. (2009), Vol. 10, No.2
118
1.
Quek SL, Tay CK, Tay KH, Toh SL, Lim KC. Pattern of third
molar impaction in Singapore Chinese: a retrospective
radiographic survey. Int J Oral Maxillofac Surg 2003; 32:
548-52.
2.
Liedholm R, Knutsson K, Lysell L Rohlin M. Mandibular
third molars: oral surgeons’ assessment of the indications
for removal. Br J Maxillofac Surg 1999;37:440-3.
3.
Obienchina AE, Arobita JT, Fasola AO. Third moar
impaction: evauation of the symptoms and pattern of
impaction of mandibular third molar teeth in Nigerieans.
Odontostomatol Trop 2001; 24: 22-5.
4.
Guven O, Keskin A, Akal UK. The incidence of cysts and
tumors around third molars. Int J Oral Maxiilofac Surg
2000; 29: 131-5.
5.
Glosser JW, Campbell JH. Pathological changes
associated with radiographically ‘normal’ third molar
impaction. Br J Maxillofac Surg 1999;37:259-60.
6.
Nordenram A, Hultin M, Kjellman O, Ramstrom G.
Indications for surgical removal of mandibular third molar.
Study of 2,630 cases. Swed Dent J 1987;11:23-9.
7.
Knutsson K, Brehmer B, Lysell L, Rohlin M. Pathoses
associated with mandibular third molars subjected to
removal. Oral Surg Oral Med Oral Pathol Oral Radiol
Endod 1996; 82:10-7.
8.
Lysell L, Rohlin M. A study of indications used for removal
of mandibular third molars. Int J Oral Maxillofac Surg
1988;17:161-4.
9.
Bruce RA, Frederickson GC, Small GS. Age of patients
and morbidity associated with mandibular third molar
surgery. J Am Dent Assoc 1980;101:240-5.
Journal of Nepal Dental Association (2009), Vol. 10, No. 2, Jul.-Dec., 119-121
Original Article
Comparison of duration of orthodontic treatment with and
without extraction among orthodontic patients
Bhattarai P1, Shrestha RM2, Mishra P3
1
Associate Professor, 2Assistant Professor, Kantipur Dental College and Hospital, 3Professor, National Academy of Medical Sciences
Abstract
Objective: To compare the effectiveness and duration of orthodontic treatment between Nepalese orthodontic
patients with extraction and with non-extraction treatment basis.
Materials and methods: A total of two hundred orthodontic patients with proportional number of patients treated
on extraction and non-extraction basis were evaluated from two exclusive orthodontic practice centers. All patients
were treated with Straight Wire brackets. Transferred patients and previous orthodontically treated patients were
excluded from the study.
Result: The average duration of orthodontic treatment was 28.5 months for all orthodontic patients with no statistical
difference between the extraction and non-extraction groups. The study however found that the treatment for
those with extraction cases were more likely to take longer duration clinically than the non-extraction cases.
Key words: Duration, Extraction, Non-extraction
Introduction
The extraction versus non-extraction debate is one of
the earliest and most lasting philosophic controversies
of orthodontic practice with both biologic and mechanical
ramifications1-3. In clinical practice many orthodontic
patients are obviously concerned about the duration of
time that they will be required to wear fixed orthodontic
appliances. Estimates of treatment duration would also
be useful to clinicians for efficient office management.
Treatment duration is affected by several variables4
such as treatment basis (extraction vs. non-extraction),
sex (male vs. female), age group (adolescent vs. adult),
and malocclusion type. Furthermore, other variables like
missing appointments, breakage of appliance, patient
co-operation (i.e. wearing of elastic, bite plate etc.),
number of dental arches treated, number of treatment
phases etc. may also contribute to longer duration of
orthodontic treatment. Most of the authors believe that
the duration of orthodontic treatment mainly depend on
patient co-operation5-7.
treatment basis affect the duration of orthodontic
treatment among Nepalese orthodontic patients.
Materials and methods
Orthodontic records were obtained from two exclusive
orthodontic practice centers with subjects treated
with Straight Wire appliance. A total of 200 patients
comprising of 101 patients treated with extraction
basis and 99 patients treated with non-extraction basis
were analyzed for the study. 80 patient records were
collected from Department of Orthodontics, People’s
Dental College and Hospital (PDCH), Kathmandu, and
120 from The Orthodontic Center (TOC), Kathmandu.
Consecutively treated cases starting from June 15, 2002
and completing by June 15, 2007 were evaluated.
The start of treatment was defined as the date of first arch
wire placement and completion of treatment as the date
on which fixed appliances were debonded completely.
Only those cases with complete pre-treatment and posttreatment records comprising of study models and written
treatment records were included. Transferred cases, two
The objective of the present study was to compare
and evaluate how the extraction versus non-extraction
Correspondence
Dr. Prakash Bhattarai, Associate Professor, Kantipur Dental College and Hospital, Kathmandu
E-mail: [email protected]
119
J. Nepal Dent. Assoc. (2009), Vol. 10, No.2
obvious clinical difference of 5.9 months between the
extraction and non-extraction cases, there is however
no statistical difference between them. The result shows
that the obtained p-value of 0.08 is very near to the level
of significance (0.05).
phase treatment protocol patients, single arch treated
patients and previous orthodontically treated patients
were excluded from the study. All treatment duration
were converted to nearest of months.
All subjects were treated with Straight Wire appliance
with Roth prescription of tip and torque. All bracket
slots were 0.018 and brackets were placed at right
angles to the long axes of the teeth. Round, square
and rectangular arch wires were used as required; and
elastics, headgear, ‘T’ loops, ‘L’ loops and key-hole loops
were used routinely.
The present data is supported by Chua et al10 whose
mean treatment duration for the extraction group wass
33.9 months, which is longer than that of non-extraction
group (25.6 months). The present data is also supported
by Fink et al11 who found the extraction duration is
longer than the non-extraction duration. It is interesting
to note their finding that each premolar extraction adds
0.9 months of duration or 1.8 months for two premolar
extraction case and 3.6 months for a case with four
premolars extraction. Another interesting finding by
him is that every degree increase in mandibular plane
decrease the 0.3 months of duration of orthodontic
treatment. In contrast to present finding, Vig et al4 found
that the duration of extraction case is slightly shorter
(31.2 months) than the non-extraction cases (31.3
months).
All data were fed into SPSS software (version 12).
The independent t-test was performed to compare the
difference between the extraction and non-extraction
treatment basis. The level of significance was set at
0.05.
Result
The result of the present study is shown in Table 1.
The study shows that the mean duration of orthodontic
treatment with extraction is 31.4 months and with
non-extraction is 25.5 months respectively. The mean
duration of orthodontic treatment for all orthodontic
patients was 28.5 months with no statistical difference
between the extraction and non-extraction groups. The
study however found that the treatment for those with
extraction cases were more likely to take longer duration
clinically than the non-extraction cases.
Summary and conclusion
The average duration of orthodontic treatment was 28.5
months for all orthodontic patients with no statistical
difference between the extraction and non-extraction
groups. Differences in duration of treatment were
apparent clinically when extraction and non-extraction
patients were compared. Treatment for those who had
tooth extractions were more likely to take longer period
of time.
Table 1: Treatment duration according to treatment
basis (in months)
Extraction
31.4
NonAverage
extraction
25.5
28.5
Acknowledgement
The Authors heartily acknowledge People’s Dental
College and Hospital and its Department of Orthodontics
for allowing us to use its data for the present research.
We would also like to thank Ms. Abhigyna Adhikari for
her help in statistical analysis procedure of the study.
p-value Significance
.081
NS
(NS: not significant)
Discussion
The average duration of treatment among Nepalese
orthodontic patients according to present study is 28.5
months. The result is shorter than the report given by
Vig et al4, which reported a mean duration of 31 months;
and longer than the report of Alger8 which reported a
mean of 22 months.
References
Most of the authors believe that there is association
between increase in duration of treatment and extraction
of tooth for treatment purpose. It is so because those
patients whose treatment procedures involve tooth
extractions generally possess much severe malocclusion
compared to those treated on non-extraction basis9.
Table 1 shows average treatment duration of 25.5 months
for non-extraction cases and 31.4 months for extraction
cases with a difference of 5.9 months. Though there is
J. Nepal Dent. Assoc. (2009), Vol. 10, No.2
120
1.
Angle EH: Malocclusion of the teeth.7th ed. Philadelphia:
SS White Dental Mfg. Co.; 1907.
2.
Case CS.: Dental orthopedia. Chicago: C. S. Case Co.;
1908.
3.
Tweed CH: Indications for the extraction of teeth
in orthodontic procedures. Am J Orthod Oral Surg
1944;30:405-28.
4.
Vig PS, Weintraub JA, Brown C, Kowalski CJ: The
duration of orthodontic treatment with and without
extractions: a pilot study of five selected practices. Am J
Orthod Dentofacial Orthop 1990;97:45-51.
5.
Allan TK, Hodgson EW: The use of personality
measurements as a determinant of patient cooperation in
an orthodontic practice. Am J Orthod 1968;56:433-40.
6.
Starnbach HK, Kaplan A: Profile of an excellent orthodontic
patient. Angle Orthod 1975;45:141-5.
7.
Slakter MJ, Albino JE, Fox RN, Lewis EA : Reliability and
stability of the orthodontic patient cooperation scale. Am
J Orthod 1980;78:559-63.
8.
Alger DW: Appointment frequency versus treatment time.
Am J Orthod Dentofacial Orthop 1988;94:436-9.
9.
treatment. Am J Orthod Dentofacial Orthop 1995;107:32934.
O’Brien KD, Robbins R, Vig KW, Vig PS, Shnorhokian
H, Weyant R. The effectiveness of Class II, Division 1
121
10.
Chua AL, Lim JY, Lubit EC: The effects of extraction
versus nonextraction orthodontic treatment on the growth
of the lower anterior face height. Am J Orthod Dentofacial
Orthop 1993;104:361-8.
11.
Fink DF, Smith RJ. The duration of orthodontic treatment.
Am J Orthod Dentofacial Orthop 1992;102:45-51.
J. Nepal Dent. Assoc. (2009), Vol. 10, No.2
Journal of Nepal Dental Association (2009), Vol. 10, No. 2, Jul.-Dec., 122-124
Original Article
Metronidazole for the prevention of dry socket after removal of
impacted mandibular third molar in Nepalese patients
Pant N1
1
Assistant Professor, Deptartment of Oral & Maxillofacial Surgery, Kantipur Dental College & Hospital, Kathmandu, Nepal
Abstract
Aim: The main purpose of the study was to see whether Metrodinazole plays a role in reducing the incidence of
dry socket after extraction of mandibular third molars.
Method: A total of 119 patients were evaluated out of which 59 patients were given a single dose of 1200 mg
Metronidazole 45 minutes prior to the surgical extraction of third molar. The other 60 patients were not given any
prophylactic dose of Metronidazole.
Result: Out of the fifty nine patients who were given Metronidazole prior to the surgical procedure, 16.95% of
the patients developed dry socket and among the other 60 patients who were not given Metronidazole, 21.67%
developed dry socket.
Conclusion: Metronidazole used as a prophylactic antibiotic for prevention of dry socket after extraction of
mandibular third molars has little or no role in preventing dry socket.
Key words: Third molar Surgery, Prevention Antibiotic prophylaxis
Introduction
Dry socket which is also known as Alveolitis Sicca
Dolorosa, ASD or Alveolar Osteitis is a common
complication after removal of teeth, particularly after
surgical extraction of mandibular third molars. The
incidence varies from a few percent to 68% depending
on the location of the removed tooth/teeth1. It is a painful
condition that usually occurs after few days following the
removal of mandibular third molars and can be treated
using antibiotics. Dry socket occurs when the blood
clot at the site of extractions is dislodged, exposing the
underlying bone and nerve endings causing significant
pain. Patient presenting with dry socket can manifest
any of the features like fever, severe jaw pain, facial
swellings, and lymphadenopathy.
menstrual cycle, smoking habits and prolonged use of
antimicrobial drugs and mouth rinses can also have a
role in the development of dry socket2-7.
Aim and Objective
The aim of this study was to see whether 1200 mg
Metronidazole given as a single dose before extraction
of impacted mandibular third molars reduced the
incidence of dry socket. The 1200mg was chosen as the
appropriate dose to ensure a high serum concentration
of Metronidazole for a couple of hours after the surgical
procedure.
Method
A total of 119 patients between 17- 30 years of age
participated in the study. The patients were healthy and
were not taking any other medications. All the 119 patients
were treated within a period of 6 months.The patients
were referred for removal of either unilateral and/or
bilateral mandibular third molars and were treated at the
Department of Oral and Maxillofacial Surgery, Kantipur
Dental College, Basundhara, Kathmandu, Nepal.
Even though the precise cause of dry socket remains the
subject of study, researchers suspects several factors
may be at play ,including bacterial contamination of
socket, difficult or traumatic tooth extraction, remaining
roots or tooth/root fragments in the socket, type of
impacted teeth, presence of pericoronitis etc. Other
factors such as age, gender, use oral contraceptives,
Correspondence
Dr. Neeraj Pant, Assistant Professor, Department of Oral & Maxillofacial Surgery, Kantipur Dental College & Hospital, Kathmandu, Nepal
E-mail: [email protected]
J. Nepal Dent. Assoc. (2009), Vol. 10, No.2
122
of bone removed (depth and volume). The collected
data have been presented using percentage, mean and
t-test.
A criteria for inclusion of the case was that a surgical
flap had to be reflected for removal of the tooth/teeth.
Patients with acute pericoronitis were treated only after
the symptoms of pericoronitis had ceased.
On the postoperative recall visit after five days, the
following data were noted: The presence of pain, the
amount of swelling, presence of any foul odour and/or
alteration of taste, and the presence or absence of blood
clot. The diagnosis of dry socket was done on the basis
of the following criteria: Absence of blood clot in the
tooth socket, and continuous increasing postoperative
pain from second postoperative day onwards.
Among the 119 patients, 1200 mg Metronidazole
was given as a single dose to 59 patients and for the
remaining 60 patients Metronidazole was not given.
Three 400-mg tablets (1200mg), were taken orally 45
minutes before starting the surgical procedure.
All extractions were done under local anesthesia using
Lidocaine hydrochloride with 2% adrenalin. After giving
the mandibular, lingual and the buccal nerve block, an
incision was made from 37 / 47 and continued posteriorly
beyond 38 / 48 upto the ascending ramus of the mandible,
then the mucoperiostal flap was raised. If the tooth could
not be extracted in one piece, it was split with surgical
burs. During drilling of bone and tooth, a constant
irrigation was done with sterile saline. After removal of
the tooth, the socket was carefully cleaned using sterile
saline and the mucoperiostal flap was repositioned
and sutured using 3-0 silk non resorable suture. All the
patients were given the same postoperative instructions,
and were prescribed analgesic tablets for the following
5 days.
Before starting the procedure the purpose of the study
was fully explained to the patients and also a written
detail of the procedure was provided to the patients.
Statistical analysis and data
Patient profile
Out of the 119 patients, 52 (43.70%) were males and
the remaining were females (60) (56.30). Twenty nine
patients (24.37%) had a history of smoking and 41
patients (34.45%) had a history of pericoronitis. The
details are shown in Table 1.
Results
Out of the 59 patients who were given Metronidazole, 10
(16.95%) developed dry socket and among the other 60
who did not take Metronidazole 13 (21.67%) developed
dry socket. Thus, there is no evidence of difference in
proportion of dry socket in patients who took and those
who didn’t take Metronidazole. i.e. (P>0.05).
The following data were recorded just before the surgical
procedure: Age, sex, smoking habits and history of
pericoronitis. The data recorded immediately after the
operation were: The duration of extraction procedure,
the amount of saline used for irrigation, and the amount
Table 1: Comparison between the two groups: number of patients.
Metronidazole group (n=59)
Non Metronidazole group(n=60)
Total
Male
22
30
52
Female
37
30
67
Yes
14
15
29
No
45
45
90
Yes
21
20
41
No
38
40
78
Sex
Smoking
History of pericoronitis
Amount of bone removed (mm³)
None
2
6
8
1-10mm³
22
22
44
11-20mm³
23
21
44
>21mm³
12
11
23
Yes
10
13
23
No
49
47
96
Dry socket
123
J. Nepal Dent. Assoc. (2009), Vol. 10, No.2
References
Discussion
Earlier studies of the efficacy of Metronidazole, with
different designs, have shown different results. Ritzau
et al9 showed no prophylactic effect of a single dose
of 800mg Metronidazole, which was also seen in the
present study.
1.
Alexander RE. Dental extraction wound management :
a case against medicating postextraction sockets. J Oral
Maxillofac Surg 2000;58:538-51
2.
Larsen P. Aveolar osteitis after surgical removal of
impacted mandibular third molars. Oral Surg Oral Med
Oral Pathol 1992;73:393-7.
In an earlier study a higher incidence of dry socket was
found after removal of partially erupted teeth than after the
removal of impacted teeth (31% and 9%, respectively).
Partially erupted lower third molar teeth have a
pericoronal pouch, these pericoronal pouches may be
heavily infected¹º. In infected pericoronal pouches there
is mixed anaerobic and facultative anaerobic flora with
large number of spirochetes, Porphyromonas species
and other gram negative bacteria, and similar flora have
also been found in the distal pocket of the adjacent
second molars¹¹. These bacteria produce protease, have
fibrinolytic activity¹² invade the surrounding tissue, and
have other metabolic activities. For such gram negative
bacteria, Metronidazole can be the drug of choice.
3.
Chiapasco M, Crescentini M, Romanoni G. Germectomy
or delayed removal of mandibular impacted third
molars: the relationship between age and incidence of
complications. J Oral Maxillofac Surg 1996;53:418-28.
4.
Heasman PA Jacobs DJ. A clinical investigation into
the incidence of dry socket. Br J Oral Maxillofac Surg
1984;22:115-22.
5.
Sweet JB, Butler DP. Predisposing and operative factors:
effects on the incidence of localized osteitis in mandibular
third molar surgery. Oral Surg Oral Med Oral Pathol 1978:
44 14-20
6.
Tjernberg A. Influence or oral hygiene measures on the
development of alveolitis sicca dolorosa after surgical
removal of mandibular third molars. Int J Oral Surg 1979;
8:30-4.
The finding that a single dose of metronidazole was
ineffective in preventing the development of dry socket
seems to argue against a microbial aetiology of dry
socket. However, recent findings on the increased
antimicrobial resistance of bacteria organized in biofilms
may explain this. The mechanism of this increased
antibiotic resistance has not yet been established, but
may be a result from the establishment of functional
mixed-species consortia into bioflim, where the cells
have a modified metabolism compared with that in
their planktonic stage13. This was seen in another study
where P. Gingivalis was 160 times more resistance to
Metronidazole in vitro when grown as a biofilm than
when grown in suspension14.
7.
Kleinbaum DG. Logistic regression, a self-learning text.
New York: Springer; 1992.
8.
Rood JP, Murgatroyed J. Metronidazole in the prevention
of dry socket. Br J Oral Maxillofac Surg 1979/1980;17:6270.
9.
Ritzau M,Hillerup S, Branebjerg PE, Ersboel BK. Does
metronidazole prevent alveolitis sicca dolorosa? Int J
Oral Maxillfac Surg 1992;21:299-302.
10.
Leung WK, Theilade E, Comfort MB, Lim PL. Micribiology
of the pericoronal pouch in mandibular third molar
pericoronitis. Oral Microbiol Oral Immunol 1993;8:30612.
11.
Mombelli A, Buser D, Lang NP, Bertold H. Suzpected
periodontopathogens in erupting third molar sites of
periodontally healthy individuals. J Clin Periodontol 1990;
17: 48-54.
12.
Cortellini P, Pini Prato G, Clauser C. Fibrinolytic activity
of human gingival in the presence or absence of plaque
bacteria. J Periodont Res 1992: 27; 34-9.
13.
Gilbert P, Das J, Foley I. Bioflim susceptibility to
antimicrobials. Adv Dent Res 1997;11:160-7.
14.
Wright TL, Ellen RP, Lacrois JM, Sinnadurai S, Mittelman
MW. Effects of metronidazole on Porphyromonas
gingivalis bioflims. J Periodont Res 1997;32:473-7.
Conclusion
Although systemic antibiotics are regularly used after
surgical procedures to prevent and cure infection of
the surgical wound, the use of 1200 mg Metronidazole
as a prophylactic antibiotic 45 minutes prior to the
surgical procedure to prevent the development of dry
socket after extraction of mandibular third molars is not
necessary as it plays little or no role in the prevention of
dry socket. However, if the extraction socket is infected,
then Metronidazole along with other systemic antibiotics
are commonly prescribed for reducing the infection.
J. Nepal Dent. Assoc. (2009), Vol. 10, No.2
124
Journal of Nepal Dental Association (2009), Vol. 10, No. 2, Jul.-Dec., 125-127
Case Note
Calcium hydroxide in management of large periapical lesion
Dixit PB1, Acharya S2, Prajapati I3
1
Lecturer, 3House Officer, Dental Department, Kathmandu Medical College, 2Lecturer, Dental Department, KIST Medical College
Abstract
The success of root canal treatment is based on total elimination of root canal content, thorough cleaning
and shaping of canal and obturation of root canal system. Calcium hydroxide is recommended as intra-canal
medicament because of its antibacterial properties, tissue dissolving ability, inhibition of tooth resorption and
indication of tissue repair by hard tissue formation. Here we present a case report, where calcium hydroxide
was used as an inter appointment endodontic dressing for management of large periapical radiolucency for six
months. Follow up after six months of treatment completion revealed complete bone regeneration in the areas
where there was extensive bone loss.
Key words: Calcium hydroxide, Periapical lesion
Introduction
Periapical lesions in most of the cases can be classified
as periapical granuloma, periapical abscess and
periapical cysts and it cannot be differentiated from each
other based on radiograph alone, although there is a
trend towards increased incidence of cysts among larger
lesions1. Dental trauma is often associated with the
disruption of pulp blood supply, leading to pulp necrosis.
This circulatory breakdown causes tissue necrosis and
anaerobic conditions for the growth of opportunistic
microorganisms2. The success of root canal treatment is
based on total elimination of root canal content, thorough
cleaning and shaping of canal and obturation of root
canal system. There are various armamentariums,
irrigants and medicaments available to perform root
canal therapy. One of the medicaments is Calcium
hydroxide which was first used in dentistry in 1930 by
Herman3. Though calcium hydroxide is not a restorative
material by itself it is used in various clinical situations
and often forms a part of restoration. Calcium hydroxide
is advocated as an inter-appointment endodontic
therapeutic dressing because of its antibacterial effect
on most of the microorganisms identified in the root
canal system4. The antimicrobial properties of calcium
hydroxide are directly related to its pH5.
of swelling on the anterior region of lower jaw. Patient
gave a history of trauma on lower anterior teeth two years
back. On clinical examination there was swelling and pus
discharge around the lower incisors. Orthopentamogram
(OPG) was advised which revealed a well defined large
radiolucency in relation to 31, 32, 41, & 42 (Fig 1)
Treatment planning was discussed with the patient and
his family before starting the procedure. Access was
opened, pus was drained from 31, 32, 41 & 42, canals
were irrigated with normal saline and closed dressing
was placed. In the following appointment, working length
was determined, canals were cleaned & shaped using K
and H files (MANI, Inc. Japan) and a closed dressing
was placed in all the involved teeth. Patient was recalled
after one week, canals were irrigated with 3% sodium
hypochlorite (Novo Dental Pvt. Ltd., India) & saline,
dried with paper points, and calcium hydroxide (RC Cal,
Prime Dental, India) dressing was placed after which
the canals were filled with temporary cement (Caviton
GC Corporation, Japan). This procedure was repeated
once every month for five times (Fig 2). Patient was
advised to report to the hospital if he experienced pain
or discomfort and/or the temporary restoration came out.
After five months, the canals were obturated using AH
plus (Dentsply Maillerfer, Switzerland) sealer and gutta
percha (Dentsply, France SAS) and the access cavities
were restored with GIC (GC Corporation, Japan).
Patient was recalled after 6 months for follow up. IOPA
was made which showed bone formation around the
Case Report
A 12 year old patient reported to dental department of
Kathmandu Medical Teaching Hospital with a complaint
Correspondence
Dr. Punam Basnet Dixit, Lecturer, Dental Department, Kathmandu Medical College & Teaching Hospital, Sinamangal, Kathmandu, Nepal
E-mail: [email protected]
125
J. Nepal Dent. Assoc. (2009), Vol. 10, No.2
Fig 1: Large radiolucency involving lower incisors
Fig 2: Recall visit after 3 months with calcium hydroxide
dressing
Fig 3: Follow up after after 6 months, healed periapical
radioluvency with bone formation
periapical areas of all the four root canal treated incisors
where there was extensive bone loss seen, initially (Fig
3).
tissue repair by hard tissue formation11. Lethal action of
calcium hydroxide on bacterial cells are probably due to
damage to the bacterial cytoplasmic membrane, protein
denaturation and damage to DNA12.
Discussion
Various studies have shown that root canals in teeth
with pulp necrosis and chronic periapical reactions have
predominance of anaerobic microorganisms, especially
the gram negative5,6. Gram negative microorganisms
not only contains virulent factors and produces toxic
products in periapical tissues, but contain endotoxin
in their cell wall7. Endotoxin in root canal may induce
radiographically visible apical reactions, show intense
inflammatory infiltrate, increase in the thickness of
periodontal ligament and resorption of cementum and
alveolar bone8. Therefore management of the teeth with
pulp necrosis and chronic periapical reaction should
not only be concerned with bacterial death, but also the
inactivation of endotoxin. Study by Assed S et al8 shows
that Calcium hydroxide detoxifies bacterial endotoxin.
Calcium hydroxide is not categorized as a conventional
antiseptic, but is clinically effective in eliminating
microorganisms from root canal space. Calcium
hydroxide is recommended as intra canal medicaments
because of antimicrobial properties4, tissue dissolving
ability9, inhibition of tooth resorption10, and induction of
J. Nepal Dent. Assoc. (2009), Vol. 10, No.2
When endodontic failure occurs, endodontic retreatment
is advised either with or without periapical surgery.
Theoretically it is better to do retreatment without
periradicular surgery. It is better to remove the old filling
material and reprepare and refill the root canal system
than to perform periradicular surgery13. The success rate
for periradicular surgery is lower than that of root canal
retreatment has already been shown14. Whether it is root
canal therapy or retreatment, infection control lies at the
heart of endodontics.
Calcium hydroxide for endodontic use comes as a
paste form which can be easily introduced into the
canal. It is a strong alkaline substance, which has a
pH of approximately 12.5. In an aqueous solution,
calcium hydroxide dissociates into calcium and hydroxyl
ions. The antimicrobial action of calcium hydroxide is
related to the release of hydroxyl ions in an aqueous
environment15. Calcium hydroxide, with its long acting
antimicrobial and tissue solvent properties plays
important role in endodontics16.
126
Conclusion
Total elimination of microorganism from the canals is
the main key to success of endodontic treatment. Use
of calcium hydroxide as an intra-appointment dressing
may help to eliminate surviving bacteria in the canal and
help to achieve a successful endodontic treatment.
teeth with chronic apical periodontitis detected by
immunofluorescence. Endod Dent Traumatol.1996;12:66-9
8.
Assed S, Paulo NF, Leonardo MR, Marcos AR. Effect of
calcium hydroxide on bacterial endotoxin in vivo. J Endod
2002;28:94-8
9.
Bhaskar SN. Periapical lesion-types, incidence and
clinical features. Oral Surg, Oral Med, Oral Pathol. 1966;
21:657–71.
Hasselgren G, Olsson B, Cvek M. Effects of calcium
hydroxide and sodium hypochlorite on the dissolution of
necrotic procine muscle tissue. J Endod 1988;14,125-7
10.
Soares J, Santos S, Silveira F, Nunes E. Nonsurgical
treatment of extensive cyst-like periapical lesion of
endodontic origin. Int Endod J 2006;39: 566–75,
Tronstad L. Root resorption etiology, terminology
and clinical manifestations. Endod Dent Traumatol
1988;4:241-52
11.
Foreman PC, Barnes IE. A review of calcium hydroxide.
Int Endod J 1990;23:283-97
12.
Siqueira JF, Lopes HP. Mechanisms of antimicrobial
activity of calcium hydroxide: a critical review. Int Endod J
1999;32:361-9
13.
Lovdahl PE. Endodontic Retreatment. DCNA 1992;36:47390
14.
Grung B,Molven O, Halse A.Periapical surgery in a
Norwegian county hospital: follow up finding of 477 teeth.
J Endod 1990;16:411-4
15.
Safavi KE, Dowden WE, Introcaso JH, Langland K. A
comparision of antimicrobial effects of calcium hydroxide
and iodine potassium iodide. J Endod 1985;11:454-6
16.
Fava LR. Calcium hydroxide in endodontic treatment
after two nonsurgical and two surgical failures: report of a
case. Int Endod J 2001;34:72-80
References
1.
2.
3.
H.A. Zander; Reaction of the Pulp to Calcium Hydroxide;
J Dent Res 1939;18; 373
4.
Bystro MA, Claesson R, Sundqvist G. The antibacterial
effect
of
camphorated
para-monochlorophenol,
camphorated phenol and calcium hydroxide in the
treatment of infected root canals. Endod Dent Traumatol
1985;1:170–5.
5.
Evans M, Davies JK, Sundqvist G, Figdor D. Mechanisms
involved in the resistance of Enteroccocus faecalis to
calcium hydroxide. Int Endod J 2002;35:221-8
6.
Abou-Rass M, Bogen G. Microorganisms in closed
periapical lesions. Int Endod J 1998;31:39-47
7.
Assed S, Ito IY, Leonardo MR, Silva LA, Lopatin D.
Anaerobic microorganisms in root canals of human
127
J. Nepal Dent. Assoc. (2009), Vol. 10, No.2
Journal of Nepal Dental Association (2009), Vol. 10, No. 2, Jul.-Dec., 128-130
Case Note
Goldenhar syndrome: A report of a rare case
Dali M1, Chacko V2, Rao A3
Specialist Resident, 2Assistant Professor, 3Professor, Department of Pedodontics and Preventive Dentistry, Manipal College of Dental
Sciences, Mangalore
1
Abstract
Goldenhar syndrome is a rare condition described by Goldenhar in 1952. It is characterized by a combination of
anomalies: dermal epibulbar cysts, auricular appendices, malformation of the ears, hypoplasia of malar bones,
mandible and zygomatic arch. The etiology of this rare disease is not fully understood, as it has shown itself
variable genetically and of unclear causes. In this report we present a case of Goldenhar syndrome in a 4-year-old
boy, who presented all classical signs of this rare condition.
Key words: Goldenhar syndrome, Facial palsy, Anophthalmos, Microtia
Introduction
Goldenhar syndrome is a rare condition and the estimated
incidence of this disorder is 1 per 5800 births with male:
female ratio of 3:2. It is a presumably inherited condition,
causing morphological abnormalities in the parts that
developed from the first and second branchial arches
during blastogenesis. It has a multifactorial etiopathology
that includes nutritional and environmental factors1.
Facial palsy7 though rare has been associated with it.
A case of Goldenhar Syndrome, with association of
anophthalmos and calcification of falx cerebri is also
reported8.
Goldenhar first described this condition in 1952 as
a disease that presents a combination of several
anomalies such as dermal epibulbar tumors, periauricular appendices and malformation of the ears.
It is also referred to as oculo-auriculovertebral (OAV)
dysplasia and hemi facial microsomia2.
In this article we present a case report of 4 years old boy
diagnosed with Goldenhar syndrome.
The presence of anomalies of the ear (microtia) and of
appendices on the ear is necessary for diagnosis of this
syndrome.
Case report
A 4 years old boy reported to our clinics for routine dental
treatment. The child was born to a young healthy parents
(non-consanguinous). The prenatal and antenatal
period was un-eventful and there was no relevant family
history.
The characteristic features of this syndrome are
epibulbar
dermoids,
dacryocystitis,
auricular
abnormalities, preauricular appendages, preauricular
fistulas, hypoplasia of the malar bones, mandible and
zygomatic arch. Some associations recorded in the
literature are macrostomia, micrognathia, high vaulted
cleft palate, bifid tongue, malocclusion and other dental
abnormalities3.
The physical features of the child was atypical with
facial asymmetry, coloboma of middle 3rd of upper right
eyelid, microtia with accessory preauricular tags, malar
hypoplasia and severe unilateral mandibular hypoplasia
(Fig 1, Fig 2 & Fig 3A). History revealed that right sided
macrostomia was surgically closed and the scar was
seen on the corner of the mouth (Fig 3B) and epibulbar
dermoids had been surgically removed by Department
of Ophthalmology when the patient was six months old.
No behavioral problem was noted during examination.
Some authors have also pointed out facial muscle
hypoplasia, vertebral abnormalities, anomalies of the
eyes1, disturbances of the central nervous system, visceral
anomalies4, Cardiac5 and genitourninary6 abnormalities.
Correspondence
Dr. Arathi Rao, Professor, Department of Pedodontics and Preventive Dentistry, Manipal College of Dental Sciences, Light House Hill
Road, Mangalore 575001, Karnataka State, India, E-mail: [email protected]
J. Nepal Dent. Assoc. (2009), Vol. 10, No.2
128
Fig 1: Right malar hypoplasia Fig 2: Coloboma of middle 3rd of Fig 3: Right side of the face Fig 4: Deviation of mandible to
and asymmetry of face
upper right eyelid
showing
right side on opening the mouth
(A) Preauricular
tags
deformed pinna
and
(B) Scar resulting from surgical
closure of macrostomia
The patient was already evaluated by a Paediatrician
and an Ophthalmologist. His cardiac function, eyes
and sight were found to be normal. Audiological testing
reports showed that both auricular structures and
hearing were normal.
Most cases have sporadic autosomal dominant and
autosomal recessive modes of inheritance. Trisomy
of 7, 22 have been described in association with
Goldenhar syndrome11. Reports indicate that several
teratogenic agents such as retinoic acid, primidone, and
thalidomide, have produced this syndrome in infants
born to pregnant women exposed to those agents12. In
our case there was no history of maternal drug intake,
any febrile illness or diabetes during pregnancy.
Dental examination revealed normal intra-oral soft
tissues and all deciduous teeth were present. Few of
the teeth in the left mandibular molar and upper anterior
region were decayed. Mouth opening was not restricted,
but the mandible deviated to the right side on maximum
opening (Fig 4).
Although this syndrome presents some similarities with
the Treacher-Collins syndrome, it is now considered a
distinct entity. The features of Treacher-Collins syndrome
are most frequently bilateral without ocular and aural
anomalies13.
The patient was subjected to many examinations and
treatments since birth and thus was very uncooperative
at present in the clinical set up. Hence the patient was
very uncooperative and the radiographic evaluation was
not possible in this case.
Delayed development of a tooth has been encountered in
some cases although this is rare14 but was not observed
in the present case. In the present case the deviation
of the mandible to the right was due to the lack of the
vertical and sagittal mandibular development, causing
the mandible to rotate bodily to the right.
Discussion
In approximately 10 to 33 percent of affected individuals,
malformations are bilateral affecting both sides of the
body, with one side typically more affected than the
other (leading to asymmetry). In the majority of such
cases, the right side is more severely affected than the
left10. The presented case also showed right side of the
face more severely affected than left side.
Prognosis of this disease is good in otherwise
uncomplicated cases without any systemic associations.
The treatment of the disease varies with age and systemic
associations and is mainly cosmetic in uncomplicated
cases.
Goldenhar syndrome can be distinguished by varying
degrees of vertebral, cardiac and sometimes structural
kidney defects which were not present in this case.
The patient exhibited clinical characteristics of complex
Goldenhar syndrome with, including facial asymmetry,
hypoplasia of the mandible, malar hypoplasia,
macrostomia, preauricular tags, coloboma of eyelid.
The dental treatment rendered to this child was
restoration of the decayed teeth. Maxillary and
mandibular orthognathic surgery is indicated followed
by future orthodontic treatment. Reconstruction of
mandibular hypoplasia can be done with rib grafts
and underdeveloped maxilla can be lengthened by
bone distraction device in future. Plastic surgery for
coloboma of eye and reconstruction of external ear
has been planned to be done at 6-8 yrs of age by an
opthalmologist.
Despite the reported frequency of cardiovascular
alterations ranging from 5 to 58%, the reported patient
had no cardiovascular alterations. Hearing disturbance
or Facial nerve dysfunction were also not present.
129
J. Nepal Dent. Assoc. (2009), Vol. 10, No.2
References
1.
Reddy P. Facio-auricular vertebral syndrome- a case
report. Indian Journal of Human Genetics 2005;13:156-8.
2.
Altamar R J. Syndrome de Goldenhar – A propósito de
um caso. An Otorrinolaringol Iber Am.1998;25:491-7.
3.
Pinheiro AL, Araujo LC, Oliveira SP, Sampaio MC, Freitas
AC. Goldenhar’s Syndrome - case report. Braz Dent J
2003;14:67-70.
8.
Grundfast KM, Guarisco JL, Thomsen JR, Koch B.
Diverse etiologies of facial paralysis in children. Int J
Pediatr Otorhinolaryngol 1990;19: 223-39.
9.
Vatwani V, Verma N, Palta SC. Rare associations with
Goldehar Syndrome. Indian Pediatr 1994; 31: 72-3.
10.
Rao VA, Rao S. Lamba PA. Goldenhar’s syndrome.
Indian J of Opthamol 1982;30: 147-9.
4.
Rodriguez JI, Palacios J, Lapunzina P. Severe axial
anomalies in the oculo-auriclo-vertebral (Goldenhar)
complex. Am J Med Genet 1993;47:69-74.
11.
Sugit Kumar GS, Haran R P, Rajshekhar V. Delleman
syndrome with Goldenhar overlap. J Pediatr Neurosci
2009;4:53-5.
5.
Lessick M, Vasa R, Israel J. Severe manifestations of
oculo auriculo vertebral spectrum in a cocaine-exposed
infant. J Med Gen 1991;28:803-4.
12.
R Kapur, R Kapur, S Sheikh, S Jindal, S Kulkarni.
Hemifacial microsomia: A case report. J Indian Soc Pedod
Prevent Dent 2008; 26: 34-40.
6.
Morrison PJ, Mulholland HC, Craig BG, Nevin C. Cardio
vascular abnormalities in the oculo-auriculo-vertebral
spectrum (Goldenhar Syndrome). Am J Med Genet 1992;
44: 425-8.
13.
Mehta B, Nayak S. Goldenhar syndrome with unusual
features: A case report. Indian J Dermatol Venereal Leprol
2008; 74: 254-6.
14.
7.
Ritchey ML, Norbeck J, Huang C, Keating MA, Bloom DA.
Urologic manifestations of Goldenhar syndrome. Urology
1994; 43: 88-91.
Alkumru H, Colok G. Hemifacial microsomia and
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J. Nepal Dent. Assoc. (2009), Vol. 10, No.2
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Journal of Nepal Dental Association (2009), Vol. 10, No. 2, Jul.-Dec., 131-132
Case Note
Use of toothbrush in maxillofacial surgery
Sagtani A1, Sybil D2
1,2
Assistant Professor, Department of Oral & Maxillofacial Surgery, College of Dental Surgery, BPKIHS, Dharan, Nepal.
Abstract
Thorough debridement is essential for the initial management of contaminated facial wounds to prevent permanent
tattooing of facial scars and remove the need for secondary facial aesthetic surgery. We used a simple toothbrush
for cleaning a contaminated wound with satisfactory results.
Facial wounds are almost always contaminated and more so if the etiology is road traffic accident. Good cleaning
and debridement of a wound is essential for healing in an orderly fashion. Facial tissues have to be delicately
handled as esthetics play an important role. We used a simple toothbrush for cleaning a contaminated wound with
satisfactory results.
Key words: Toothbrush, Debridement of contaminated wounds
Case report
A 35 year old female patient was brought to the
emergency department with history of road traffic
accident. Her vitals were stable and she showed no signs
of head injury. On local examination, she had extensive
soft and hard tissue injury over the left frontozygomatic
region. The force of trauma had caused stripping of soft
tissue from the underlying bone. The soft tissue wound
had ragged margins and was highly contaminated
with road debris (Fig 1). There was no loss of tissue.
There was a comminuted fracture of left zygomatic
complex. Her vision was not impaired. She was taken
up for repair under general anesthesia. A medium nylon
bristled toothbrush was used to remove the embedded
debris from the subcutaneous tissue and muscle (Fig 2).
Thorough debridement was done using copius amounts
of saline and povidone-iodine solution until the wound
was clean (Fig 3). The zygomatic complex fracture was
reduced and fixed. The ragged margins were finely
trimmed, tissue approximated and sutured in layers. The
sutures were removed on 7th post-operative day. The
wound healed with no infection and minimal scarring.
Fig 1: Facial wound contaminated with dirt
Discussion
No wound can heal in an orderly fashion unless it is
clean, healthy, and free of contamination. Thorough
debridement is essential for the initial management
of contaminated facial wounds to prevent permanent
Fig 2: Use of toothbrush for debridement
Correspondence
Dr. Alok Sagtani, Deptartment of Oral & Maxillofacial Surgery, College of Dental Surgery, BPKIHS, Dharan, Nepal.
E-mail: [email protected]
131
J. Nepal Dent. Assoc. (2009), Vol. 10, No.2
Facial tissues, especially the subcutaneous tissues and
muscles, require gentle handling due to their delicate
nature. Aggressive scrubbing to remove dirt or dust with
a stiff nylon brush can be used on the facial dermis.
But this can damage an already frayed subcutaneous
tissue and muscle. A toothbrush, however, provides a
suitable alternative. It removes dirt from tissues without
damaging them. The small flaps can be held in hand
and scrubbed gently using a toothbrush with medium
to hard bristles. A toothbrush can also be used in an
emergency setting where sophisticated debridement
equipment is not available. The other advantages of a
toothbrush are it is readily available, can be sterilized
and is cost effective.
Fig 3: After debridement
Thus we recommend the use of toothbrush for cleaning
any contaminated facial wound prior to suturing.
tattooing of facial scars and remove the need for
secondary facial aesthetic surgery. Time spent in
removing foreign bodies and dirt at this stage will be
repaid one hundred fold in the months to come1.
References
Although mechanical cleansing with salinesoaked
sponges effectively removes bacteria, it damages the
wound and impairs its resistance to infection2. Mechanical
abrasive scrubbing techniques and surgical excision
can lead to blood loss and the loss of viable tissue. The
conventional abrasive methods, e.g. plastic scrubbing
brush, plastic pan scrub, or diathermy tip scratch pad, are
sufficient for debridement of contaminated limb or torso
wounds because of their flat skin surfaces3. Ultrasonic
debridement is a viable option for the management of
contaminated facial wounds3,4.
J. Nepal Dent. Assoc. (2009), Vol. 10, No.2
132
1.
Rowe and Williams. Maxillofacial Injuries. Vol 1. 2nd ed,
Churchill Livingstone, 1994.
2.
Rodeheaver GT, Smith SL, Thacker JG, Edgerton MT,
Edlich RF. Mechanical cleansing of contaminated wounds
with a surfactant. Am J Surg 1975; 129: 241–245.
3.
L. H.-H. Cheng, J. Stewart, M. Thompson, D. M. Adlam.
Ultrasonic debridement of contaminated facial wounds.
British Journal of Oral and Maxillofacial Surgery 2002; 40:
149–150.
4.
Nichter SN, McDonald S, Gabriel K, Sloan GM, Reinisch
JF. Efficacy of debridement and primary closure of
contaminated wounds: a comparison of methods. Ann
Plast Surg 1989; 23: 224–230.
Journal of Nepal Dental Association (2009), Vol. 10, No. 2, Jul.-Dec., 133-136
Case Note
Non surgical endodontic retreatment following surgical
endodontic failure: A case report
Gautam S1, Thapa A2, Pai ARV3, Kundabala M4
Lecturer, Kantipur Dental College and Teaching Hospital, Nepal, 2Specialist Resident,
India.
1
3,4
Professors, MCODS, Manipal University,
Abstract
Retreatment in endodontics provides a second chance for the patient to save the tooth that would otherwise be
deemed for extraction. Treatment approach can be either surgical or non surgical. Treatment failure can be due to
many reasons from missed canal to iatrogenic perforation which has to be evaluated carefully before initiating the
treatment. Sometimes a clinician also has to deal with inter appointment flare ups requiring prompt and efficient
patient management. This case report describes the non surgical management of failed root filled teeth which had
also been treated surgically.
Key words: Calcium hydroxide, Endodontic failure, Retreatment
of teeth. Nevertheless, it can show signs of failure due
to poor root canal treatment, faulty surgical procedure,
lack of retrofilling4.
Introduction
Conventional endodontic treatment may fail due to
various reasons and inadequate root canal treatment
with persistent infection remaining in inaccessible areas
of the canal being one of them1,2.
In case of a surgical failure, re-surgery has showed
reduced success rates compared with first-time
surgery. It has been reported that success rates were
5%–27% lower for re-surgery compared with first-time
surgery5. Further surgical procedure can be a traumatic
experience with many disadvantages like pain, edema,
discolorations and other post operative complications
which can hamper the patients daily activities. Hence
it is advisable to select a nonsurgical retreatment
wherever feasible with an emphasis on effective sealing
of infected root canal.
When patient reports to the dental clinic with severe
pain/swelling on the tooth that has previously been
root filled they are anxious and skeptic about whole of
endodontic treatment posing clinician in tricky state of
patient management. Endodontic retreatment offers the
patient a second chance to save a root canal treated
tooth that would otherwise be destined for extraction.
Such a retreatment can be carried out either surgically
or non surgically. Nonsurgical retreatment when possible
often is the first choice for attempting to correct obvious
deficiencies in the previous treatment. However, surgical
retreatment would be the choice in the presence of
certain indications like presence of an apical cyst,
anatomical or iatrogenic obstruction etc3.
Generally surgical retreatment would be carried out
following a nonsurgical endodontic failure, on the
contrary, this case report deals with the non surgical
retreatment following the surgical treatment failure of a
previously endodontically treated maxillary central and
lateral incisors.
The surgical procedure can effectively remove the
infected portion of the root colonized by bacteria either
intraradicular or extraradicular or both, thus enhancing
the chances of healing. Consequently, complete healing
after periapical surgery has been reported in 37%–97%
Case Report
A 32 years old male patient reported with severe pain on
upper front teeth since 2 days. He gave a history of root
canal treatment 2 years back followed by immediate
Correspondence
Dr. Suman Gautam, Lecturer, Department of Conservative Dentistry and Endodontics, Kantipur Dental College Teaching Hospital and
Research Center, Basundhara, Nepal, E-mail: [email protected]
133
J. Nepal Dent. Assoc. (2009), Vol. 10, No.2
medication. Patient was prescribed with medications
and scheduled for subsequent visits.
root surgery in the same teeth. He also gave history
of on and off pus discharge from the gums in that area
since 3 months. On examination, a draining sinus in
relation to apical area of left central incisor (21) was
seen (Fig 1). There was an acrylic crown in relation to
21 and a GIC restoration on maxillary left lateral incisor
(22). The teeth were tender on palpation. On an IOPA
radiograph insufficiently obturated canals were noted in
relation to 21 and 22 with blunted root apex suggestive
of previous root end surgery but with no evidence of any
retrograde filling and persistent periapical radioluscency
(Fig 2). The subjective and objective findings led to the
diagnosis of a surgical endodontic treatment failure with
chronic periapical abscess. Patient was explained about
the existing condition and the need of retreatment was
stressed. However, patient was reluctant to undergo
endodontic surgery again, therefore a nonsurgical
retreatment of the teeth was agreed.
In the following visit, the working length was determined
using an apex locator (Root ZX, J.Morita Mfg.Corp.)
followed by radiographic confirmation. As the extent
of the root canal cleaning and shaping carried out
during the previous root canal treatment could not be
determined, the canal debridement and shaping was
carried out using standardized method by inserting K
and H files (MANI, Inc. Japan) up to size 80 and filing
the canal walls for the entire working length.
The canal irrigation was carried out by alternate use
3%sodium hypochlorite (Novo Dental Pvt Ltd, India)
and 2% chlorhexideine. Following canal cleaning and
shaping Calcicur was deposited as an intra canal
medicament and the access opening was sealed with
zinc oxide eugenol cement.
The nonsurgical treatment was initiated under local
anaesthesia by removing the crown of 21, followed by
the removal of the access opening filling and guttapercha obturation from both the teeth (Fig 3). The old
gutta percha were removed using H file (MANI, Inc.
Japan) and gutta percha dissolving chemical solvent,
Xylene(Merck specialities Pvt. Ltd., India).The canal
was thoroughly rinsed with normal saline and 2%
chlorhexidine(Vishal Dentocare Pvt. Ltd., India). After
drying the canals with paper points, Calcicur (Ivoclar
Vivadent), a calcium hydroxide based intracanal
medicament was placed in the canal and temporised
with Zinc oxide eugenol cement. Patient was recalled
after one week but patient reported to the clinic after two
days with pain due to inter appointment flare up and it
was treated by allowing drainage through the root canals
of 21 and 22 followed by canal irrigation and access
opening sealing as in first visit but without intracanal
Fig 1: Clinical photo of the patient showing draining sinus
(circled area)
J. Nepal Dent. Assoc. (2009), Vol. 10, No.2
After 4 weeks of recall and change of the intracanal
medicament, the teeth become asymptomatic and the
sinus tract healed. In the next visit, the root canals
were obturated with gutta percha(Dentsply Maillefer,
Switzerland), using thermoplasticized gutta percha
master cone method as described by Kerezoudis6 using
AH Plus(Dentsply Maillefer, Switzerland) sealer and
access were sealed with composite resin (Z100,3M
ESPE) (Fig 4). The acrylic crown of 21 which was
cemented temporarily between the visits was cemented
using GIC luting cement (GC Corporation, Japan).
Patient was followed up after one month, twelve months
(Fig 5) and twenty four months (Fig 6) the teeth were
found to be asymptomatic and there was decrease
in the size of the periapical radiolucency, suggesting
progressive healing.
Fig 2: Preoperative IOPA
Radiograph
134
Fig 3: After Gutta percha removal
Fig 4: Immediate post obturation
Fig 5: 12 months recall
Discussion
Retreatment of failed root filled tooth requires thorough
examination and evaluation of the tooth in question
because decision of whether to retreat and restore or
to extract and restore can be made. Post treatment
diseases following an endodontic failure occurs due to
complex interaction between various factors explained
by Sunqvist7. The reason many teeth do not respond
to root canal treatment is because of procedural errors
that prevent the control and prevention of intracanal
endodontic infection8. Undoubtedly, the major factors
associated with endodontic failure are the persistence
of microbial infection in the root canal system and/or the
periradicular area1,2.
favourable than that of primary endodontic surgery for
post-treatment disease14.Nevertheless, going by the
periapical status, a surgical retreatment would have
looked appropriate but a nonsurgical retreatment
was still required due to the previous faulty root canal
obturations.
Inter appointment flare up that occurred may be- due
to disturbance in the microbial ecosystem -due to
inadvertent pushing of debris in the periapex- due to
over instrumentation or reaction with irrigating solution
and solvents or increased virulence of the persistent
bacteria at the periapex15. Other problems that can occur
during the retreatment that can even lead to extraction
of a tooth would be an irreparable perforation or root
fracture16, 17.
If root filled tooth has failed, there can be five possible
treatment options: To review or do nothing, root canal
retreatment, root end surgery, extraction followed
by implant or referral. Cross sectional studies from
different countries including most recent studies clearly
demonstrate that more than 30% of all root filled teeth
in the population are associated with apical periodontitis
or post treatment disease9,10,11,12. A general guideline has
been given by European Society of Endodontology13 for
indications of retreatment, they are;
•
Teeth with inadequate root canal filling with
radiological findings and/or symptoms
•
Teeth with inadequate root canal filling when the
coronal restoration requires replacement
•
Teeth with coronal dental tissue that is to be
bleached
Fig 6: 24 months recall (decrease in
size of periapical lesion is evident)
A nonsurgical retreatment regimen employing
through canal shaping, effective canal irrigation using
combination of 2% chlorhexidine and 3% sodium
hypochlorite followed by canal disinfection using
calcium hydroxide between the visits was followed.
This regimen was employed as its efficiency has been
proved in many studies in eliminating the intraradicular
infection18, 19,20,21,22. Additionally it has been seen that the
non surgical retreatment shows improved outcomes
with increasing recall time5, 23.
Further, obturation using customized gutta percha
facilitated obtaining a good apical seal, which mattered
most in this patient as it ensured endodontic success
based on nonsurgical treatment alone. In the recall
time of one month, one year and two years patient was
asymptomatic and there was progressive decrease in
the size of the lesion indicating periapical healing. This
benefitted the patient by sparing him from the need for a
reendodontic surgery.
In this patient nonsurgical retreatment was carried out
as the patient was reluctant to undergo reendodontic
surgery due to its traumatic nature and associated
post operative problems. It has also been shown that
the outcome of repeated endodontic surgery was less
135
J. Nepal Dent. Assoc. (2009), Vol. 10, No.2
Conclusion
There is enough potential for success of primary
root canal filling but fact remains that clinicians are
confronted with post treatment disease. Endodontic
retreatment could be a suitable option in case of a
post treatment disease following an endodontic failure.
Nonsurgical procedures could look of minor importance
or insignificant during retreatment, for managing surgical
endodontic failure especially when reendodontic surgery
appears inevitable. However, with non surgical treatment
approach and adequate apical and coronal sealing we
can achieve favourable clinical outcome even in case of
failed surgically treated teeth.
10.
Kabak Y. Abbott Prevalence of apical periodontitis and
the quality of endodontic treatment in an adult Belarusian
population. Int Endod J 2005; 38: 238–45.
11.
Loftus JJ, Keating AP, McCartan BE. Periapical status
and quality of endodontic treatment in an adult Irish
population. Int Endod J 2005 ; 38: 81–6.
12.
Tsuneishi M, Yamamoto T, Yamanaka R, Tamaki N,
Sakamoto T, Tsuji K, Watanabe T. Radiographic evaluation
of periapical status and prevalence of endodontic
treatment in an adult Japanese population. Oral Surg Oral
Med Oral Pathol Oral Radiol Endod 2005; 100: 631–5.
13.
Abbott PV.Factors associated with continuing pain in
endodontics.Aust Dent J 1994;39(3):157-61.
14.
Nair PNR, Sjogren U, Krey G, Sundquvist G. Therapy
resistant foreign body giant cell granuloma at the periapex
of a root-filled human tooth. J Endod 1990; 16: 589–95.
Gagliani MM, Gorni FGM, Strohmenger L. Periapical
resurgery versus periapical surgery: a 5-year longitudinal
comparison. Int Endod J 2005; 38:320–27.
15.
Lin LM, Skribner JE, Gaengler P. Factors associated with
endodontic treatment failures. J Endod. 1992; 18(12):6257.
Richard E. Walton. Interappointment flare-ups: incidence,
related factors, prevention, and management. Endod
Topics 2002; 3: 67–76.
16.
Stabholz A, Friedman S.Endodontic retreatment case
selection and technique.Part 2: Treatment planning for
retreatment. J Endod 1988; 14(12):607-14.
17.
Kvinnsland I,Oswald RJ,Halse A, Gronningsaeter AG.A
clinical and roentgenological study of 55 cases of root
perforation. Int Endod J 1989;22(2):75-84.
References
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Min-Kai Wu & Paul R. Wesselink. Timeliness and
effectiveness in the surgical management of persistent
post-treatment periapical pathosis. Endod Topics
2005;11:25-31.
4.
Ingle JI, Bakland LK, Baumgartner JC. Ingle’s Endodontics,
6th ed, Hamilton Ontario: BC Decker Inc; 2008.
18.
Edgar Schafer. Irrigation of the root canal. Endo 2007;
1(1):11-27.
5.
Torabinejad et al. Outcomes of non surgical retreatment
and endodontic surgery: A systematic review. J Endod
2009;35:930-7.
19.
6.
Kerezoudis NP, Valavanis D, Prountzos F. A method of
adapting gutta-percha master cones for obturation of
open apex cases using heat. Int Endod J 1999; 32: 5360.
Kuruvilla JR, Kamath MP. Antimicrobial effect of 2.5%
sodium hypochlorite and 0.2% chlorhexidine gluconate
separately and combined as endodontic irrigants. J
Endod 1998;24:472.
20.
Sundqvist G, Figdor D. Life as an endodontic pathogen
Ecological differences between the untreated and rootfilled root canals. Endod Topics 2003; 6: 3–28.
Ahmad Zamany, Kamran Safavi, DMD, Larz S. W.
Spangberg. The effect of chlorhexidine as an endodontic
disinfectant. Oral Surg Oral Med Oral Pathol Oral Radiol
Endod 2003; 96:578-81.
21.
Siqueira Jr JF, Lopes HP. Mechanisms of antimicrobial
activity of calcium hydroxide: a critical review. Int Endod J
1999; 32:361-69.
Zahed Mohammadi, and Paul V. Abbott. Antimicrobial
substantivity of root canal irrigants and medicaments: A
review. Aust Endod J 2009; 35: 131–39.
22.
Boucher Y, Matossian L, Rilliard F, Machtou P.
Radiographic evaluation of the prevalence and technical
quality of root canal treatment in a French subpopulation.
Int Endod J 2002; 35: 229–238.
Estrela C, Sydney GB, Bammann LL, Felippe Júnior O.
Mechanism of action of calcium and hydroxyl ions of
calcium hydroxide on tissue and bacteria. Braz Dent J
1995;6(2):85-90.
23.
Cristian et al.Treatment outcome in endodontics: The
Toronto study-phases 3 and 4: Orthograde retreatment.
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Journal of Nepal Dental Association (2009), Vol. 10, No. 2, Jul.-Dec., 137-139
Case Note
Pyogenic granuloma associated with bone loss: A case report
Singh VP1, Nayak DG2, Upoor AS3
1
Post Graduate Student, 2,3Professors, Department of Periodontics, Manipal College of Dental Sciences, Mangalore, Karnataka, India.
Abstract
Diverse group of pathologic process can produce the enlargement of soft tissues in the oral cavity and often present
a diagnostic challenge. These soft tissue enlargement may represent a variation of normal anatomic structure,
inflammatory reaction, cyst, neoplasm and developmental anomalies. A group of reactive hyperplasias which
develop in response to a chronic recurring tissue injury that stimulates an excessive tissue reapair response. The
pyogenic granuloma is a reactive enlargement that is an inflammatory response to local irritation such as calculus,
a fractured tooth, rough dental restoration and foreign materials and rarely associated with bone loss. This article
present a rare case of pyogenic granuloma associated with bone loss in a 28 year old female.
Key words: Bone loss, Pyogenic granuloma, Reactive hyperplasias
Introduction
Pyogenic granuloma (PG) or granuloma pyogenicum is
a common tumor-like growth of the oral cavity or skin that
is considered to be non-neoplastic in nature. Pyogenic
granuloma is a kind of inflammatory hyperplasia. The
term pyogenic is a misnomer in that, contrary to the
name implies, the lesion does not contain pus. Pyogenic
granuloma is a benign lesion; therefore surgical
excision is the treatment of choice. To avoid possibility
of recurrence the lesion must be excised down to the
under lying periosteum and predisposing irritant must be
removed.
Intraoral examination revealed a solitary diffused
growth, red in color, measuring around 2x2x1.5 cm seen
in interdental region in relation to the right lateral incisor
and canine and extending palatally (Fig 1). Lesion had
palatally rough surface, while superior surface showed
indentation of the lower teeth as a result of surface
ulceration. The growth was pedunculated and attached
to the palatal mucosa between the teeth. Mobility of
upper permanent lateral incisor was grade-II and that
of canine was grade –I. Pathological migration of the
canine was also present. Oral hygiene of the patient
was fair.
Case report
A 28 year old systemically healthy female patient
presented with a chief complaint of growth in the mouth
involving upper right front region of the jaw. The patient
had noticed a small painless growth about 6 years
back. There was a very gradual increase in size, which
led to discomfort while eating as the extent of growth
had reached the occlusal plane (Fig 1). Patient also
complained of gradual increase in the space between
right maxillary lateral and canine. There was no history
of intake of any hormonal supplements.
Intraoral periapical radiograph of teeth 12 and 13
region revealed widening of periodontal ligament
space, horizontal interdental bone loss with change in
trabecular pattern of bone. Roots of the involved teeth
did not show any signs of resorption (Fig 2). Occlusal
radiogarph showed the similar findings as intraoral
periapical radiograph and no expansion of bony plates
was observed.
The hemogram of patient was within normal limits and
excisional biopsy was done under local anaesthesia.
Lesion was excised deep to the periosteum and
the biopsy specimen was sent for the microscopic
examination (Fig 3). After complete stoppage of
Extraoral examination did not reveal any facial
asymmetry. Lymph nodes were not palpable.
Correspondence
Dr. Vijendra Pal Singh, Post Graduate Student, Department of Periodontics, Manipal College of Dental Sciences, Mangalore, India
E-mail: [email protected]
137
J. Nepal Dent. Assoc. (2009), Vol. 10, No.2
Fig 1: Pre-operative lesion
Fig 2: Intraoral periapical
radiograph showing interdental
bone loss and change in
trabecular pattern in between
lateral incisor and canine.
Fig 4: Complete healing after two month of
excision
Fig 5: Photomicrograph showing endotheliumlined channels, Mixed inflammatory cell infiltrate
consisting predominantly of neutrophils and
lymphocytes
bleeding periodontal pack was given. Patient revisited
after one week for removal of the periodontal pack. The
excised area was again repacked with periodontal pack
for one more week to facilitate healing. One week later,
periodontal pack was removed and satisfactory healing
of the gingiva was seen. Complete healing of the excised
area was observed at two month follow up visit (Fig 4).
Discussion
Although pyogenic granuloma may occur in all ages1,2
it is predominant in the second decade of life in young
adult females, possibly because of the vascular effects of
female hormones3,4 Some authors believe that patients
are mostly males under 18 years of age, females in the
age range 18 to 39, and older patients with an equal
gender distribution.
Histopathological findings in the photomicrograph
shows Hematoxilin-Eosin stained section showing
highly vascular connective tissue exhibiting numerous
small and large endothelium-lined channels engorged
with red blood cells. Thickened wall of blood vessels,
proliferating endothelial cells and few lymphatic vessels
were evident. Mixed inflammatory cell infiltrate consisting
predominantly of neutrophils and lymphocytes were also
seen (Fig 5). The overlying epithelium had hyperplastic
parakeratinized stratified squamous epithelium exhibiting
areas of pseudoepitheliomatous hyperplasia. The above
histopathological features was suggestive of pyogenic
granuloma.
J. Nepal Dent. Assoc. (2009), Vol. 10, No.2
Fig 3: Excised lesion
The principal oral site affected by pyogenic granuloma
is the gingiva. Other oral sites are the lower lip, tongue,
buccal mucosa, upper lip, and palate. These findings are
consistent with those of others2,5,6. With regard to site,
gingival pyogenic granuloma is more common in the
maxilla than in the mandible and in the anterior region
than in the posterior regions of both jaws5,6.
Some studies7,8 concluded that some initial traumatic
condition is the main etiologic factor for development
of pyogenic granuloma. It has been reported that 80%
of patients with extragingival oral pyogenic granuloma
gave positive information about preceding injury9 to the
site.
138
It is now generally accepted that the lesion is an
exaggerated localized connective tissue reaction to
minor injury or irritation. Gingival irritation as a result of
calculus, overhanging edges or rough restorations might
be the predisposing factor for the development of gingival
pyogenic granuloma. It is possible that microulceration
from these irritants in an already inflamed gingiva allows
the ingress into the gingival connective tissue of low
virulent oral microflora. This evokes an exaggerated
vascular hyperplastic response in the connective tissue
resulting in the formation of pyogenic granuloma6.
Definitive diagnosis after histolpathologic exeamination
was suggestive of pyogenic granuloma.
References
Clinically, PG is a smooth or lobulated exophytic lesion
manifesting as small, red erythematous papules on
a pedunculated or sometimes sessile base, which
is usually hemorrhagic and compressible. The size
varies in diameter from a few millimeters to several
centimeters3,4. Rarely does PG exceed 2.5 cm in size
and it usually reaches its full size within weeks or
months, remaining indefinitely thereafter10. Clinical
development of the lesion is slow, asymptomatic and
painless3,4 but it may also grow rapidly11. The surface
is characteristically ulcerated and friable12 which may
be covered by a yellow, fibrinous membrane13 and its
color ranges from pink to red to purple, depending on
the age of the lesion. Young PGs are highly vascular in
appearance3 because they are composed predominantly
of hyperplastic granulation tissue in which capillaries
are prominent. Thus minor trauma to the lesion may
cause considerable bleeding, due to its pronounced
vascularity3,13, whereas older lesions tend to become
more collagenized and pink3. Rarely, PG may cause
significant bone loss, as reported by Goodman-Topper
and Bimstein14. In our case also, slight bone loss was
associated with pyogenic granuloma.
Pyogenic granuloma is a benign lesion; therefore,
surgical excision is the treatment of choice. Although
conservative surgical excision and removal of causative
irritants (plaque, calculus, foreign materials, source of
trauma) are the usual treatments3,4,15 for gingival lesions,
the excision should extend down to the periosteum
and the adjacent teeth should be thoroughly scaled to
remove the source of continuing irritation3.
Differential
diagnosis
of
pyogenic
granuloma
includes parulis, peripheral giant cell granuloma,
peripheral ossifying fibroma, hemangioma, peripheral
fibroma,
leiomyoma,
hemangioendothelioma,
hemangiopericytoma, bacillary angiomatosis, kaposis
sarcoma, metastatic tumour, pregnancy tumor and post
extraction granuloma16.
In our case, the differential diagnosis after clinical
examination and radiographic observation were
peripheral giant cell granuloma and pyogenic granuloma.
139
1.
Lawoyin JO, Arotiba JT, Dosumic OO. Oral pyogenic
granuloma: A review of 38 cases from Jhadan, Nigeria. Br
J Oral Maxillofac Surg 1997; 35:185-9
2.
Al-Khateeb T, Ababneh K. Oral pyogenic granuloma in
Jordanians: a retrospective analysis of 108 cases. J Oral
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3.
Neville BW, Damm DD, Allen CM, Bouquot JE. Oral
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4.
Regezi JA, Sciubba JJ, Jordan RCK. Oral pathology:
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Lee L, Miller PA, Maxymiw WG, Messner HA, Rotstein
LE. Intraoral pyogenic granuloma after allogeneic bone
marrow transplant. Report of three cases. Oral Surg Oral
Med Oral Pathol 1994;78: 607- 10
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Bragado R, Bello E, Requena L, Renedo G, Texeiro
E, Alvarez MV, Castilla MA, Caramelo C. Increased
expression of vascular endothelial growth factor in
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Hagiwara K, Khaskhely NM, Uezato H, Nonaka S. Mast
cell “densities” in vascular proliferations: a preliminary
study of pyogenic granuloma, portwine stain, cavernous
hemangioma, cherry angioma, Kaposi’s sarcoma,
and malignant hemangioendothelioma. J Dermatol
1999;26:577-86
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Macleod RI, Soames JV. Epulides: a clinicopathological
study of a series of 200 consecutive lesions. Br Dent J
1987;163:51-3
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Bouquot JE, Nikai H. Lesions of the oral cavity. In
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Sternberg SS, Antonioli DA, Carter D, Mills SE Oberman
H. Diagnostic surgical pathology 3rd ed, Philadelphia:
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Esmeili T, Lozada-Nur F, Epstein J. Common benign oral
soft tissue masses. Dent Clin North Am 2005;49:223-40
12.
Greenberg MS, Glick M. Burket’s oral medicine: diagnosis
and treatment. 10th ed, Hamilton: BC Decker; 2003. p.
141-2
13.
Bachmeyer C, Devergie A, Mansouri S, Dubertret L,
Aractingi S. Pyogenic granuloma of the tongue in chronic
graft versus host disease. Ann Dermatol Venereol
1996;123:552-4 (in French)
14.
Goodman-Topper ED, Bimstein E. Pyogenic granuloma
as a cause of bone loss in a twelve-yearold child: report
of case. ASDC J Dent Child 1994;61:65-7
15.
Eversole LR. Clinical outline of oral pathology: diagnosis
and treatment. 3rd ed, Hamilton: BC Decker; 2002 p. 113-4
16.
Kerr DA. Granuloma pyogenicum. Oral Surg Oral Med
Oral Pathol 1951;4:158-76.
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Journal of Nepal Dental Association (2009), Vol. 10, No. 2, Jul.-Dec., 140-146
Case Note
Orthodontic mini implant: Versatile application for clinical
enhancement
Xia CS1, Ding Y2, Kafle D3
Professor, 3Resident, Department of Orthodontics, Zhengzhou University, Henan, China, 2Associate Professor, Department of
Orthodontics, Beijing University Second Dental Centre, Beijing, China.
1
Abstract
The use of Orthodontic mini implant (OMI) anchorage is rapidly growing these days. In the recent years it has
become a compulsory tool for orthodontist. With the better understanding of the biomechanics not only all kinds of
tooth movement is possible with mini implant but orthopedic and orthognathic like effects can also be produced with
judicious application of this device. Here we present two cases treated with the help of OMI. The first case needed
maximum anchorage due to the degree of crowding and protrusive facial profile. The conventional orthodontic
treatment could have produced good result but the ideal result was possible only with the absolute anchorage
using mini implant. In the second case there was supra eruption of left maxillary second premolar and first molar.
The OMI was used to intrude the supra erupted teeth. The almost impossible tooth movement with conventional
orthodontic treatment was possible with the insertion of these implants buccally and palatally, within a period of six
months and without any side effects.
Key words: Orthodontic mini implant(OMI), Anchorage, Centre of resisitance, Intrusion, Retraction
During the last two decades, the orthodontic mini
implant (OMI) has progressed so much that now it is the
everyday armamentarium of an orthodontist. A thorough
review of the literature finds that implants for the
orthodontic purposes were tried even before Branemark
who introduced the dental implant1,2. The screws used
for the internal fixation of the fracture sites were used for
the orthodontic purposes. Initially stainless steel, then
vitallium and now titanium screws are used. However,
except few case reports the regular and advanced
use of orthodontic mini implants started around the
beginning of the new millennium. In 1970 Linkow
described the prosthetic implant for orthodontic purpose
in a case report3. He presented six cases treated with
the help of blade implants. After that regular prosthetic
implants were used for the orthodontic anchorage. It
undoubtedly served the orthodontic speciality for many
years and still are used in some multi disciplinary cases.
Those implants were tried even in retro molar area and
tuberosity areas for the sake of orthodontic anchorage.
However the biggest disadvantage of these implants
was their size which confined their placement only in
edentulous ridges or retro molar areas.
In the search of small dimension implants and with the
idea of surgical screws, the present day orthodontic mini
implants were developed. The first purely orthodontic
implant dates back to 1983. Greekmore et al inserted
surgical screw just below the anterior nasal spine to
reduce the anterior deep bite4. The implant was made
of vitallium and served the orthodontic purpose reducing
the deep bite by 6 mm in one year time period. Roberts
et al did several animal experiments in the eighties.
They had inserted 2mm diameter implants in the femur
of the dogs and rabbits with high success rate but
similar result were not found in oral cavity5. Block and
Hoffman in 1995 discovered onplant and used palate
as an anchorage source6. In 1997 Kanomi used the
1.2mm diameter implant for orthodontic purpose7. Since
then there have been floods of case reports and clinical
researches on mini-implant anchorage. Now there are
different designs of orthodontic implants in the market.
The continuous modification of the design is still going on
and is an on going process. Due to its small dimension
(< 2mm in diameter), it can be placed in most of the
areas like inter radicular space, mid palatal suture, paramedian area of palate, retro molar areas etc. and can be
Correspondence
Dr. Dashrath Kafle, Resident, Department of Orthodontics, Zhengzhou University, Henan, China
E-mail: [email protected]
J. Nepal Dent. Assoc. (2009), Vol. 10, No.2
140
used for multiple purposes like de-crowding, orthodontic
camouflage, molar distalization, mesialization, intrusion,
segmental intrusion, vertical control and treatment of the
canted occlusal plane.
and forward flairing teeth (Fig 1). Her cephalometric
analysis (Fig 2) revealed her ANB angle to be 5 degrees
with slightly high mandibular plane angle. She was
diagnosed to be class II skeletal malocclusion with
crowding due to maxillary excess. Her detailed pre
treatment cephalometric analysis is shown in Table 1.
Another important advantage of orthodontic implant is
its non invasive placement procedure. Flap raising in not
needed and most of the implants are drill free (self drilling)
which eliminates the extensive surgical procedures and
expensive implant kits. They can be inserted under
topical anesthesia. The local anesthesia of adjacent
teeth is better avoided for the purpose of patient having
sensation of pain if implant touches the tooth roots or
periodontal ligaments instead of interradicular alveolar
bone. This phenomenon is described as bio-feedback
mechanism in a recent article by Brumgartel S8.
Considering her facial profile and degree of crowding,
the treatment plan was to extract the upper and lower
first premolars. Her anchorage plan was either to put
two micro implant in maxilla or use Trans Palatal Arch
(TPA) and headgear. After discussing the treatment
plan with the patient, she agreed with the first option.
The treatment was started with pre-adjusted edgewise
appliance, 0.022 ×0.028 inch MBT bracket. Two OMIs
were inserted in between upper first molar and second
premolar, one on each side. The anterior teeth were
retracted by active tie-back from the crimpable hook
to the implant (Fig 3). 200gram of force was applied
on each side. The post treatment photographs shows
improved facial profile and ideal occlusion with class I
molar and canine relation, ideal over jet and overbite
(Fig 4). Her post treatment cephalometric analysis is
shown in Table 1. Total duration of treatment time was
20 months.
Noteworthy to mention here, the prosthetic implants
are invariably osseo-integaterd. Due to this property,
their retention is very stable but one must wait at least
4-6 months before using them for occlusal restoration
or orthodontic loading. The orthodontic mini implants
used today interestingly are not Osseo-integrated rather
they are attached with the bone mechanically. Using
the property of mechanical stability, the orthodontic
implants can be loaded immediately for orthodontic
purpose unlike prosthetic implants in which we have
to wait at 4-6 months. Initially a light force (50-100
grams) is used, later this force can be increased up
to 200-250 grams which is adequate enough for the
orthodontic tooth movement. The success rate of these
implants is very high but of course proper selection of
anatomic site is very important. The success rate of
more than 90% is reported in many clinical trials9-12.
However overnight success of this frequency should
not be expected. The learning and experiencing curve
is always very steep. OMI can be used to move teeth
with absolute preservation of anchorage on regular
basis. However implant assisted orthopedic and
orthognathic like treatment is now possible13,14. Molar
intrusion once considered to be almost impossible tooth
movement by conventional orthodontic mechanism,
is now easily possible with orthodontic mini implants.
Finally the orthodontic implants are far cheaper than
dental implants, non-invasive, predictable and reliable.
They can be easily removed even with out any kind of
anesthesia.
Table 1: Cephalometric data
Measurement
SNA
SNB
ANB
Interincisal(II)
SN-GO ME
MX1-SN
MX1-NA (angle)
MX1-NA(mm)
MAN1-NB(angle)
Man1-NB(mm)
Normal
82±3
80±3
2±2
131±6
32±4
108±4
22±3
4±2
25±3
4±2
Pretreatment
84
79
5
115
33
114
30
6
30
6
Post treatment
82
80
2
128
30
107
24
6
24
3
Case 2
A 36 years old female patient was referred to the
orthodontic department by her prosthodontist. Her lower
left second premolar and molars were missing due to
which the upper second premolar and first molar had
supra erupted (Fig 6). Due to this supra eruption, the
restoration of lower edentulous area was not possible.
The treatment plan was OMI assisted orthodontic
intrusion of upper left second premolar and first molar so
that lower edentulous area could be restored with dental
implant. Two mini implants were inserted, one buccally
and the other palatally. Second pre-molar was bonded
while first molar was banded. The teeth were then
intruded with elastic chain and Ni-Ti closed coiled spring
(Fig 7). The total treatment duration was 6 months. The
post-treatment photographs show well intruded teeth
and lower edentulous area restored with dental implant
(Fig 8).
Here we report two cases which were treated in the
Department of Orthodontics, Second dental centre
of Beijing University and Department of Orthodontics,
Zhengzhou University, China.
Case 1
A 23 years old female patient came to the Department
of Orthodontics with the chief complaints of irregular
141
J. Nepal Dent. Assoc. (2009), Vol. 10, No.2
Case 1
Figs 1: (Case 1) Pre-treatment photographs showing crowding and protrusive profile
Figs 2: (Case 1) Pre-treatment OPG, Cephalogram and Cephalometric Tracing
J. Nepal Dent. Assoc. (2009), Vol. 10, No.2
142
Figs 3: (Case 1) During treatment, upper en-masse retraction with orthodontic mini implant
Figs 4: (Case 1) Post-treatment facial and intra-oral photographs
143
J. Nepal Dent. Assoc. (2009), Vol. 10, No.2
Figs 5: (Case 1) Post treatment OPG, Cephalogram and Cephalometric tracing
Case 2
Figs 6: (Case 2) Pre-treatment facial and intra-oral photograph
Figs 7: Photographs at the start of treatment, during treatment and at the completion of treatment
Figs 8: Extra-oral and intra-oral photographs after occlusal restoration with dental implant
J. Nepal Dent. Assoc. (2009), Vol. 10, No.2
144
Conclusion
Mini-implant anchorage can produce highly predictable
results with decreased treatment time and decreased
side effects. Mini implant anchorage has expanded the
horizon of orthodontic treatment towards orthognathic
like effects remaining within the boundary of orthodontic
domain.
Discussion
In the first case, we decided to put two mini-implants in
maxilla because of the need of maximum anchorage.
Maximum anchorage can be obtained by the use of
extra oral appliance e.g. headgear,TPA and OMI. But
the patient compliance is the major factor. Especially
the adult patients have poor compliance for the extraoral appliances. TPA is commonly used to preserve the
anchorage. But in cases of maximum anchorage needs,
TPA is not the reliable option. To retract the teeth bodily,
the line of applied force should pass through the centre
of resistance15,16. In our case the crimpable hook was
not long enough to reach up to the centre of resistance
of anterior teeth. This produced intrusive component in
addition to retractive component which is beneficial in
deep bite case. Orthodontic mini implant reduced the
overall treatment time8.
References
Implant anchorage cannot increase the rate of tooth
movement but it can definitely reduce the unwanted
tooth movements. Nanda described the duration of
orthodontic treatment still approaches 2 years: arguably
because of the time it takes to correct the unintended
side effects (undesirable tooth movements) that occur
during tooth treatment17.
The mini-implant anchorage has predictable outcome
which eliminates side effects. This may be the reason for
decreased treatment time. Another reason for decreased
treatment time is the anterior en-masse retraction.
Canine does not need to be retracted individually which is
usual procedure to preserve anchorage in conventional
orthodontic treatment. Mini implant anchorage can be
used to retract all the anterior teeth together.
In the second case of molar intrusion we placed two
mini implants one on the palatal side and the other on
the buccal side. Different ways of molar intrusion has
been described in literature18,19. To obtain the pure
intrusion of molar and premolar the force should again
pass through the centre of resistance, buccolingually
as well as mesiodistally. Otherwise unwanted tipping of
the tooth will result. If we can control the palatal force,
then the tooth can be intruded with implant only on the
buccal area. To obtain this mechanics, the heavy wire
trans-palatal arch can be placed which prevents buccal
tipping of the tooth. We can add palatal crown torque
in TPA to add the intrusive effect of the buccal mini
implant. If the line of force is applied through the centre
of resistance, the molar intrusion can result in a short
period of time. Usually the result can be seen within
months of treatment. In our case, it took us six months
to intrude the molar and sufficient space was available
to put implant supported teeth in the lower jaw.
145
1.
Gainsforth BL, Higley LB. A study of orthodontic
anchorage possibilities in basal bone. Am J Orthod Oral
Surg 1945;31:406-17.
2.
Branemark PI, Adell R, Breine U, Hansson BO, Lindstrom
J, Ohlsson A. Intra-osseous anchorage of dental
prosthesis. 1. Experimental studies. Scand J Plast
Reconstr Surg 1969;3:81-100.
3.
Linkow LI. Implant-orthodontics. J Clin Orthod 1970;4:68590.
4.
Creekmore TD, Eklund MK. The possibility of skeletal
anchorage. J Clin Orthod 1983;17:266-9
5.
Roberts
WE:Endosseous
miniscrews:Historical,
vascular,and integration perspectives. In: Nanda R and
Uribe FA, editors:Temporary Anchorage Devices in
Orthodontics St.Louis :Mosby-Elsevier; 2009. p. 3-13.
6.
Block MS, Hoffman DR. A new device for absolute
anchorage for orthodontics. Am J Orthod Dentofacial
Orthop 1995;107:251-8.
7.
Kanomi R. Mini-implant for orthodontic anchorage. J Clin
Orthod 1997;31:763-7.
8.
Baumgaertel S, Razavi MR, Hans MG. Mini-implant
anchorage for the orthodontic practitioner. Am J Orthod
Dentofacial Orthop 2008;133:621-7.
9.
Wilmes B, Rademacher C, Olthoff G, Drescher D.
Parameters affecting primary stability of orthodontic miniimplants. J Orofac Orthop 2006; 67:162-74.
10.
Park HS, Jeong SH, Kwon OW. Factors affecting the
clinical success of screw implants used as orthodontic
anchorage. Am J Orthod Dentofacial Orthop 2006;
130:18-25.
11.
Cheng SJ, Tseng IY, Lee JJ, Kok SH. A prospective study
of the risk factors associated with failure of mini-implants
used for orthodontic anchorage. Int J Oral Maxillofac
Implants 2004;19:100-6.
12.
Kravitz ND, Kusnoto B. Risks and complications of
orthodontic miniscrews. Am J Orthod Dentofacial Orthop
2007;131(4Suppl):43-51.
13.
Kuroda S,Katayama A,Takano-Yamamoto T. Severe
anterior open-bite case treated using titanium screw
anchorage Angle Orthod 2004;74:558-67.
14.
Liou EJW:Appliances,mechanics,and treatment strategies
toward orthognathic-like treatment results. In Nanda R
and Uribe FA Editors:Temporary Anchorage Devices in
Orthodontics, St. Louis: Mosby-Elsevier; 2009. p. 16797.
J. Nepal Dent. Assoc. (2009), Vol. 10, No.2
15.
Burstone,C.J. and H.A.Koenig.Optimizing anterior and
canine retraction. Am J Orthod 1976;70: 1-19.
16.
Yoshida N, Jost-Brinkmann PG, Koga Y, Mimaki N,
Kobayashi K. Experimental evaluation of initial tooth
displacement, centre of resistance and centre of rotation
under the influence of an orthodontic force. Am J Orthod
Dentofacial Orthop 2001;120:190- 7.
17.
strategies in Clinical orthodontics, St. Louis; ElsevierSaunders; 2005.p. 1-16.
Kulberg A, Nanda R. Principles of Biomechanics. In
Ravindra Nanda editor: Biomechanics and Esthetic
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146
18.
Park HS, Jang BK, Kyung HM. Maxillary molar intrusion
with micro-implant anchorage(MIA). Aust Orthod J 2005;
21:129-35.
19.
Melson B, Fiorelli G. Upper Molar intrusion. J Clin Orthod
1996; 30:91-6.
Journal of Nepal Dental Association (2009), Vol. 10, No. 2, Jul.-Dec., 147-150
Case Note
Endodontic management of trumatized immature nonvital
permanent anterior teeth: A case report
Pradhan RJ1
1
Lecturer, Dental Department, KIST Medical College & Hospital, Imadol, Lalitpur
Abstract
Patients who present with non-vital immature permanent teeth pose a special challenge to dentists and require
a specially tailored treatment plan. Wide tubular canals usually seen in young permanent anterior teeth often
affected by trauma pose an endodontic situation where achieving apical seal is difficult because of the wide apical
foramen with a nonconstrictve terminus.
This case report presents the clinical procedure used to produce a hard tissue barrier in the open apex, and into
which gutta percha along with the sealer was condensed by a special custom made technique.
Key words: Open apex, Calcium hydroxide, Apexification, Custom made obturation technique
Introduction
Teeth with incomplete rhizogenesis, pose a special
challenge to dentists all over because of large open
apices, divergent root walls, thin dentinal walls that are
susceptible to fracture and frequent periapical lesions.
This group requires a specially tailored treatment plan,
different from the other patients1.
The calcified material that forms over the apical foramen
has been histologically identified as an osteoid or
cementoid. Radiographic interpretation of apical closure
is often misleading3. It may need clinical determination.
Obturation of an immature tooth that has undergone
apexification is difficult as the apical portion of the canal
is often larger than the coronal portion and since the
cross-section of the canal is much wider in the labiolingual (or labiopalatal) direction than mesio distally2.
Widely accepted endodontic management of these teeth
requires cleaning and filing of the canal with temporary
paste to induce a complete calcific barrier at the apex
of the tooth for a root end closure of incompletely
developed apex. Apexification is the term to describe
this procedure. Finally different special techniques of
obturation are used against which a guttapercha root
filling can be condensed without the possibility of sealant
or gutta-percha root filling going through the apex into
the periapical tissues2.
Guttapercha is obviously the filling material of choice
because it can be packed into the irregularities that are
present in these large canals.
Lateral compaction is not the technique of choice
because the resistance of the canal walls for lateral
pressure is reduced in immature teeth and the greater
bulk of gutta-percha require an even greater force to
deform. Warm guttapercha techniques are best suited
for filling immature canals and apices. The method to
be employed will depend upon the operators preference
and expertise.
Many materials have been reported to successfully
stimulate apexification. But calcium hydroxide has its
histological importance3. This medicament has also been
shown to change the environment in the dentin and bone
to a more alkaline pH, which has been postulated to
slow down the action of the resorptive cells and promote
hard tissue formation and repair4.
Correspondence
Dr. Reema Joshi Pradhan, Lecturer (Conservative Dentistry & Endodontics), KIST Medical College & Hospital, Imadol, Lalitpur
E-mail: [email protected]
147
J. Nepal Dent. Assoc. (2009), Vol. 10, No.2
Case Report
A 10 years old boy came to the Dental Department,
KIST Medical Collge, Imadol, for the treatment of the
traumatized maxillary central incisors (Fig 1). The patient
reported that the trauma occured 6 months back and
that no treatment had been performed. There was pain
associated with both the fractured upper anterior teeth.
Clinical examination revealed crown fractures exposing
the pulp chamber of both maxillary central incisors.
One month later a radiograph of the teeth were made.
The canal were then dried and checked with 30 size
paper point for apical barrier formation. The barrier
formation was incomplete which was confirmed due to
the presence of sensitivity in the apical area and also
with the presence of blood and tissue fluid on the tip of
the paper point.
On the visit after 2 months, the same procedure was
repeated. Radiological examination showed initiation of
apical barrier formation with the reduced diameter of the
apical foramen (Fig 5). The root canal dressings were
renewed in each visit.
The tooth failed to respond to cold test with ice stick and
heat test using gutta percha cone. There was mild pain
on percussion as well. There was absence of any sinus
tract. Periapical radiographs revealed immature teeth
with open apex (Fig 2).
In the next visit which was in 3 months interval, another
radiograph was made and formation of apical barrier was
checked. On insertion of no. 30 paper point, resistance
was felt at the barrier region. The paper point was totally
dry and the tip was also frayed (Fig 6). This indicated
that the barrier formation was complete.
In first visit, access was opened using a no. 4 round bur
and coronal preparation was done by Gates Glidden bur.
Initial working length was predicted by gently advancing
a number 30 absorbent paper point along the root canal
until it was pressed against tissue at the apex and the
length was calculated by deducting the length soaked
with blood. Then the working length radiograph was
made (Fig 3) and working length was established at 1
mm short of the radiographic apex. Irrigation with 1%
sodium hypochlorite was done throughout the cleaning
and shaping procedures.
The final canal preparation was up to 130 no. file.
Obturation was done in both the teeth using customized
gutta percha technique. 2-3 standard sized gutta percha
were selected (Fig 7). The cones were then softened
with minimal amount of heat and were rolled in a glass
slab with spatula until it formed a single smooth thick
cone about the size of the canals (Fig 8 & 9). Resin
based sealer (AH plus, Dentsply) was mixed and coated
on to the manually modified guttapercha which was
inserted up to the working length. Filling was done with
glass ionomer cement (Fuji IX, GC corp). Radiograph
was made (Fig 10).
Gentle instrumentation was done with H-file from 60 to
120 no. in rasping movement. Canals were dried with
larger number of sterile absorbent paper points. A slurry
of radiopaque calcium hydroxide paste (Endocalpaste,
Insta Chemical Ltd.) was placed in the canal with a
lentulo spiral up to the full working length so that the
paste contacted the tissue at the apex. Temporary
restoration was given with reinforced zinc oxide-eugenol
cement (Fig 4). One week later, a dressing of calcium
hydroxide paste was again placed.
Fig 1: Fractured maxillary central
incisors
Fig 2: Pre-treatment
radiograph
J. Nepal Dent. Assoc. (2009), Vol. 10, No.2
One week later, little bit of the gutta percha was removed
from the pulp chamber, and final restoration comprising
of a glass ionomer lining and composite filling was
placed. Follow up visits were done at 6 months interval.
Fig 3: Working length Fig 4: Radiograph after
radiograph
placement of Calcium
hydroxide
148
Fig 5: Radiograph
showing reduced
diameter of root apex
Fig 6: Frayed end
of paper point after
barrier formation
Fig 7, 8 & 9: Preparation of customized gutta percha cone
Discussion
The endodontic management of traumatized nonvital
immature permanent anterior teeth has been reviewed.
Some traditional treatment options have stood the
test of time and are still valid to this day. Others have
been reviewed and modified with the passage of time,
as new science and new materials evolve to prove,
disprove or facilitate approaches to the management of
these cases. Practitioners need to always be aware of
changes that occur from time to time with respect to the
recommendations for treatment, and of scientific studies
that support or disprove treatment rationales1.
Fig 10: Radiograph of root
canals after obturation
with customized gutta
percha cones
growth factors and MTA (Mineral Trioxide Aggregates)
have been reported to promote apexification similar to
that found with calciumhydroxide7.
Although apexification occurs with many materials, it
has been reported even without the presence of canalfilling material after removal of the necrotic pulp tissue.
The most important factors in achieving apexification
seem to be thorough debridement of the root canal and
sealing of the tooth4.
Apical barrier formation can be expected to occur in
over 90% of teeth treated by this clinical technique. The
average length of time to achieve an apical hard tissue
barrier is 5-7 months, necessitating 2-4 visits and clinical
technique which has been shown to be successful in
96% of teeth treated with a 5-year survival rate of 86%.8
Failures are usually due to poor root canal therapy,
inadequate coronal seal or further trauma of a tooth with
an adequate root canal treatment2.
Apexification is aimed at the formation of a mineralized
barrier in the root apex in such a way that gutta-percha
can be condensed properly in the main canal space2.
Induction of apical closure has been the most widely
used approach to treating open apex3.
Calcium hydroxide has been extensively used to
accomplish apical closure due to its apparent ability
to stimulate hard tissue formation5 It was originally
introduced to the field of endodontics by Herman in
1930 as a pulp-capping agent, but its uses today are
widespread in endodontic therapy6. Then, Kaiser first
introduced the use of calcium hydroxide mixed with
camphorated monopara-chlorophenol (CMCP) to induce
apical closure. The technique was popularized later in
1966 by Frank7.
During the course of treatment by multiple visit
apexification, it showed many teeth were lost while
waiting for a calcific bridge to develop. In 1999 the
revolutionary MTA material was advocated for cases with
open apices as an apical barrier against which guttapercha was condensed, compacted or even injected6.
A one-step alternative to conventional apexification
procedures has been proposed by Koeings7. Successful
performance of a one-step procedure may benefit both
the patient and the practitioner because of the reduced
amount of office time required. The potential problem of
patient compliance is also reduced, and it appears that
reopening the root canal and recleaning during multiple
visits may disturb the process of apexification7.
Calcium hydroxide can be mixed with a number of
different substances (CMCP, distilled water, sterile
saline, anesthetic solutions and recently chlorohexidine)
to induce apical closure. The relatively good success
rate of this procedure has been attributed to one or
more of the following properties: (a) the high pH; (b) the
calcium ion; (c) the hydroxyl ion; and (d) the antibacterial
effect2.
The aim of the root filling is to completely obturate the root
canal. Instead of the lateral condensation of guttapercha
points in cases of wide canals, other methods of filling
Various other materials such as tricalcium phosphate,
collagen calcium phosphate, osteogenic protein-1, bone
149
J. Nepal Dent. Assoc. (2009), Vol. 10, No.2
regular follow up leads to optimal outcome in such types
of cases.
the root canal with guttapercha may be employed, these
include constructing a custom guttapercha point or
use of one of the heated guttapercha techniques3. The
method to be employed will depend upon the operator’s
preference and expertise.
References
Conclusion
Accidents at home, school or playground due to common
childhood activities can result in traumatic injuries to the
teeth. Upper anterior permanent central incisors are the
teeth most frequently traumatized. The comprehensive
management of these cases can increase the better
outcome of treatment.
An immature tooth that develops pulpal or periapical
disease presents special problems. Conventional root
canal treatment or any surgical approach would be
unpredictable. Apexification has been widely accepted
procedure for such cases and calcium hydroxide plays
a great role as an intracanal medicament for inducing
apical closure by formation of an apical stop8. Though,
time consuming, apical closure can be expected to occur
in over 90 per cent of non vital immature incisor teeth
treated by intracanal dressings of calcium hydroxide
paste. The five year success rate is over 85 per cent for
teeth with adequate root fillings2.
For wide canals and divergent apical portions, customized
guttapercha cone technique is a simple procedure for
obturation, which adapts easily on walls without voids8.
A thorough clinical knowledge, accurate diagnostic
techniques and meticulous endodontic procedures with
J. Nepal Dent. Assoc. (2009), Vol. 10, No.2
150
1.
Moule AJ, Moule CA. The endodontic management of
traumatized permanent anterior teeth: A review. Aust
Dent J 2007;52:(1 Suppl):S122-37.
2.
National Clinical Guidelines and Policy Documents
1999 -management and root canal treatment of nonvital immature permanent incisor teeth, Dental Practice
Board for England and Wales. www.nhsbsa.nhs.uk/
Documents/.../paediatric_dentistry_uk, 1999 (downloaded
on 21 October 2009)
3.
Cohen S, Hargreaves KM. Pathways of the Pulp, 9th ed,
Mosby Elsivier; 2009. p. 871
4.
Nunes E, de Moraes IG, de Novaes PM, Sousa SM.
Bilateral fusion of mandibular second molars with
supernumerary teeth: Case Report. Braz Dent J.
2002;13:137-41.
5.
Fidel RA, Carvalho RG, Varela CH, Letra A, Fidel SR,
Complicated crown fracture: a case report. Braz Dent J.
2006;17:83-6.
6.
Finucane D, Kinirons MJ.Non-vital immature permanent
incisors factors that may influence treatment outcome.
Endod Dent Traumatol 1999;15:273-7.
7.
Koeings JF, Heller AL, Brilliant JD, Melfi RC, Driskell
TD. Induced apical closure of permanent teeth in adult
primates using a resorbable form of tricalcium phosphate
ceramic. J Endod 1975; 1:102-6.
8.
Dominguez Reyes A, Mun˜oz Mun˜oz L, Aznar Martin
T. Study of calcium hydroxide apexification in 26 young
permanent incisors. Dent Traumatol 2005;21:141–5.
Journal of Nepal Dental Association (2009), Vol. 10, No. 2, Jul.-Dec., 151-157
Review Article
The dental applications of titanium and its alloys: A review
Rodrigues S1, Shenoy V2, Shetty T3, Jain N4
1
Associate Professor, 2,3Professors, 4Assistant Professor, Department of Prosthodontics, Manipal College of Dental Sciences, India
Abstract
The advances made in dental materials science suggest that intriguing changes will continue to occur in the
practice of dentistry. Titanium is one dental material that promises to play an important role in the materials of
the future and is a potentially important metal for medical and dental applications, currently being at the heart of
most dental implantology. Being biocompatible it is also a suitable replacement for existing alloys in fixed and
removable prostheses. Its future use in Prosthodontics would increase based on advanced research and clinical
trials. Although the reports on the prosthodontic application of titanium have been increasing, its use in clinical
dentistry for conventional removable partial denture is rather limited. This article will present the applications
of titanium and reviews the literature on its status in Prosthodontics, especially Removable Prosthodontics by
conducting an electronic search of Pub Med and reviewing English language peer reviewed articles from the years
1996-2008 coupled with additional references from citations within the articles. The articles were accessed by
using the keyword “titanium, titanium alloys, pressure casting, removable partial denture framework”.
Key words: Titanium, Titanium alloy
Introduction
Titanium is a fascinating material being the focus of
attention of dental researchers and clinicians. It has
been referred to as, “the wonder metal”, for two different
reasons1. One was because it had many unique and
wonderful properties. The other being one just had to
wonder what role titanium would play in the materials
of the future.
and devices for titanium casting has resulted in clinical
and laboratory success with titanium based alloys. Its
further use in Prosthodontics would increase based on
research and trials to compare its effectiveness to other
existing and commonly used metals. The purpose of this
article is to describe the properties of Titanium and to
review its status in Prosthodontics. A literature search
of Pub med was performed and English language
peer reviewed articles published from 1998- 2008 that
addressed the question of the properties of Titanium
and its application in Prosthodontics were included. The
Medline search was supplemented with a hand search
to identify relevant peer reviewed articles published in
dental journals.
The controversy surrounding the biocompatibility of
cobalt and nickel containing alloys as potential allergenics
and the biological risks of metal ions released in the
mouth during corrosion suggests the merits of another
base metal alloy as an alternative2. Although none of the
materials used in dentistry are totally inert, the evolution
of titanium as an economical and nontoxic biocompatible
replacement for existing alloys for fixed and removable
prosthesis has rekindled interest in this wonder metal.
Titanium: A historical perspective
Although first identified by Gregor in 1791 as Mechanite
and rechristened as Titanium by Klaproth after the
Titans of the Greek mythology it was Dr. Wilhelm Kroll
who invented useful metallurgical processes for the
commercial production of titanium and is considered to
be the father of titanium industry3,4.
Until recently, the use of titanium for casting and its
prosthodontic application was limited, probably because
of technical difficulties in the casting procedure.
Advances in research, development of new materials
Correspondence
Dr. Shobha Rodrigues, Associate Professor, Department of Prosthodontics, Manipal College of Dental Sciences, India
E-mail: [email protected]
151
J. Nepal Dent. Assoc. (2009), Vol. 10, No.2
General properties
A comprehensive review of the properties of titanium
is essential to understand its working and applicability.
Concepts have been organized to understand its
applications despite deterrents to its use. Titanium
has physical and mechanical properties, which have
led its increased use in dental prosthesis despite
casting difficulties due to high melting point (17000C),
low density, high affinity to gases, and its reactivity
with most components of most investment materials
resulting in surface contamination, the removal of which
is difficult, and complicating5,6,7. Although manufacturers
do not recommend electrolytic polishing, this procedure
may minimize residual irregularities not reached by
conventional polishing, thereby optimizing the polishing
process and providing a smoother surface8. Titanium has
low thermal conductivity (22 W/m2)9 and is considered
more physiological material than gold since its thermal
conductivity is the closest one to the enamel’s proper
value. This feature also allows for excellent localized
electric arc spot welding, though when cutting heat will
not be dissipated quickly1. Another important feature of
titanium its is ability to form a very stable oxide layer which
contributes to corrosion resistance, osseointegration and
permits close apposition to physiological fluids, proteins
and hard tissues to the metal surface10.
1) Inert gas arc- melting /gas pressure casting machines
that consist of 2 chambers:
an upper chamber (melting chamber) for arc
melting under an inert atmosphere (Argon gas)
and
•
Lower chamber (mold Chamber) with a muffle
in which the molten metal is forced under
Gravitational acceleration and inert gas pressure.
e.g. Castamatic, Dentaurum.
2) Inert gas melting /centrifugal casting machines with
vertical or horizontal centrifugal casting e.g. Cyclarc,
J Morita
3) High frequency induction melting/ gas pressure
casting machines.e.g. Tycast, Jeneric/Penetron and
Titaniumer, Ohara
Regardless of these new developments and the
advance in the equipment used, porosity associated with
titanium casting remains a problem resulting in inferior
restorations19-22. Porosity is mainly on account of the gas
entrapment due to vast temperature difference in molten
Ti and that of the investment material causing rapid
solidification, reducing the chances of gas to escape,
and eventually trapping these bubbles in the metal
casting and metal shrinkage upon solidification21,23.
These differences are more than 11000C for magnesia
based investment alloys and 16000C for silica based
investment materials23. Radiographic digital imaging
study analyses have confirmed that among the different
casting systems, the centrifugal casting systems
showed better results than other pressure differential
casting systems and Ti castings made under an argon
pressure of 50 mm Hg are significantly more porous
than are castings made under a pressure of 400 mm
of Hg. The non vented molds of a highly permeable
refractory material yield the soundest castings20,21. The
turbulent flow of molten titanium is responsible for gas
incorporation and increasing albeit smaller casting
defects in centrifugal systems. On the other hand the
laminar flow of molten metal produces fewer but larger
defects in the gas pressure/ vacuum systems5, 24-26.
Studies on the in vitro corrosion of titanium found that
the titanium ion release increased in the presence
of fluoride ions; hence chemical agents primarily
fluoridated solutions must be avoided even though
no corrosion effects were observed clinically11,12,13.
Similar studies on the corrosion resistance revealed
that corrosion resistance was inversely proportional
to surface roughness and pH of the solution12,14,15.
Spectrophotometry studies further revealed that all
titanium alloys were covered mainly with rutile type
oxide after corrosion tests16.
Studies done by Ikeda and Igarashi demonstrated
that titanium plates anodized by being discharged in
various concentrations of NaCl, Na F and KI solutions
acquired antibacterial activity, which were found to be
cell compatible suggesting greater clinical success of
implants, due to reduced colonization of oral bacteria
thus reducing one of the causes of peri-implantitis17,18.
In some situations, larger sized pores are more beneficial
than the smaller sized pores because they can be easily
detected by the laboratory radiographic units and can
be eliminated by laser welding27. However in the case
of extremely large pores, welding repair is questionable
due to the high energy required resulting in a possible
alteration of the mechanical properties28.
Titanium casting machines
The casting of titanium dental appliances was noted in
the early 1970 with the work of Water Stratt1of the US
National Institute of Standards and Technology. This
was followed by numerous studies in Japan, Europe and
USA towards the precision casting of dental prostheses,
and the development of casting machines and suitable
investment materials. Titanium casting machines are
classified into 3 types19.
J. Nepal Dent. Assoc. (2009), Vol. 10, No.2
•
Cast titanium removable partial denture
Titanium is a relative new material for removable partial
denture (RPD) frameworks. Because of its unique
mechanical and chemical properties, Titanium is an
ideal biomaterial and a suitable alternative for patients
sensitive and allergic to other metals. The combination
152
of high strength and low weight makes Titanium and its
alloys some of the highest strength/weight ratio materials,
second only to fiber glass and other highly reinforced
polymers1. On account of its low elastic modulus Titanium
requires more bulk to prevent permanent deformation
during function therefore clasps have to be wider than
usually seen with Co-Cr or stainless Steel Another
benefit of the low elastic modulus is that titanium can
engage deeper retentive undercuts on teeth without
applying lateral forces to the abutment teeth during
insertion and removal of the appliance.
fatigue life, but decreases their retention. They suggested
that activation of titanium clasps to be avoided as they
had lower fatigue resistance.
On the other hand, due to its inherent large flexibility,
cast bilateral long span RPD made in titanium are
contraindicated. These appliances are better made
of stiffer Co- Cr alloys1. One of the most common
problems that necessitate replacement of RPD’s is
fracture of metal framework. Within the framework,
clasp assemblies are cited as fracture sites29. Internal
porosity is reported as a potential factor in the fracture
mechanism because it reduces bulk of the metal and
causes stress concentration. Even with special casting
methods, titanium is prone to porosity, especially with
complicated structures. Therefore castings should be
examined with non destructive methods, for example
with radiographs. Removable partial denture frameworks
that were 0.70mm thick had better castability than did
0.35 mm thick RPD frameworks. The same study also
showed that Ti commonly failed to cast perfect mesh
specimens, although the same problem was not seen in
Co-Cr alloys30. Baltag.I. et al22 investigated the influence
of sprue design on internal porosity of circumferential
clasps of cast titanium removable partial dentures
and concluded that curved sprue design produced
significantly less porosity than conventional straight
design.
Bridgeman et al34 investigated the retentiveness of
titanium and cobalt chromium removable denture
clasps over a 3 year period of simulated clinical use,
and concluded that the flexibility and long term retentive
resiliency of the clasps made Ti and its alloys suitable
for Removable partial dentures especially for situations
involving deep undercuts. They also suggested that
though casting defects contribute to material degradation
and loss of retention in a small percentage of the titanium
and titanium alloy clasps, the risk of fracture was actually
greater for the Cobalt Chromium clasps than for the pure
titanium or titanium alloy clasps.
Vander Brink et al33. compared various RPD clasp
materials and fabrication procedures including Nickel
Titanium alloys (Ni-Ti). The alloy was found to be
unacceptable for an RPD clasp even when a 0.8 mm
diameter was used. One outcome of the study was the
need to compare materials in a curved clasp configuration
rather than in straight specimens.
Dong Suk Kim et. al35 compared the clasp retention of
Cast Ti-Ni alloys with conventional removable partial
denture clasps and found that though the end point
retention for all the clasps were similar, there was less
change in the retentive force of the cast Ti-Ni alloys after
repeated cyclic sequences of simulated placement and
removal, finding them a very desirable option for RPD
fabrication.
Titanium in crowns and bridges
A study on the marginal fit of Titanium crowns was
found to be intermediate between a group of high noble
alloy (Au-Pd-Ag) and Ni-Cr alloy crowns36. In 1989,
Andersson et.al37 introduced a new system of titanium
crowns that used a copy milling spark erosion technique
to fabricate titanium copings and veneered them with
composite resin. In this technique the external contour
of the titanium crown or coping can be shaped out of a
solid piece of titanium by a milling machine, while the
internal contour of the titanium crown is spark eroded
with a carbon electrode. Single titanium crowns can
be fabricated with this method, and multiple unit fixed
prostheses can be made by laser welding individual
units together. The advantages of this system includes
low cost, standardized fabrication and biocompatibility38.
A study on the fit of 20 cast titanium copings divided
into two equal groups with 45 and 90 degree shoulders
revealed the surface of marginal discrepancy was
greatest with the 90-degree configuration39. Casting
shrinkage occurred particularly along the horizontal axis
in the plane of the shoulder.
Blackman et al31 investigated the dimensional changes
during casting of titanium for RPD frameworks. The
authors concluded that dimensional changes in both
horizontal and the vertical planes occurred, with mean
cross arch shrinkage of 2.6% horizontally and expansion
of 1.8% vertically. Shrinkage in the premolar region
was less than that in the molar region. They concluded
that methods for best controlling factors influencing
dimensional changes need to be fully investigated.
Pekka K Vallittu et al32 studied the deflection fatigue of
cobalt chromium, titanium and gold alloy cast denture
clasp. The results of the study suggested that significant
differences exist in the fatigue resistance of removable
denture clasps made from different commercial cast
metals, which may cause loss of retention of the
removable partial denture and clasp failures. They
concluded that from a clinical standpoint activation of
cobalt chromium and gold alloy clasps lengthens their
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J. Nepal Dent. Assoc. (2009), Vol. 10, No.2
The overall fit of the spark eroded titanium crowns on
the basis of the size and character of the cement film at
three selected sites from inside the finish line was found
to be less than cast gold alloys40.
oxidation during porcelain firing and therefore improved
ceramic bonding51.
Changing titanium surface to control its high temperature
oxidation has been examined. Published studies
showed that titanium surface nitridation52 or a thin
Chromium coating is an effective method of limiting
titanium oxidation at high temperature53. Regardless
of the interfacial variables, conventional noble ceramic
bonding was superior to titanium bonding51.
Porcelain bonded to titanium
If titanium’s distinct advantage is to be used, for aesthetic
crowns and bridges, the ability to apply porcelain veneer
becomes important. Fusion of porcelain on titanium
is not without difficulties. The characteristic high
temperature oxidation of titanium is the main obstacle
to strong titanium bonding5, 41-44 Kirmura et al45 reported
the oxidation effects of the porcelain titanium interface
reaction. They concluded that the thickness of TiO2 on
commercially pure titanium surface increased with the
increase in oxidation temperature. Titanium surface
hardness also increased substantially after oxidation
at and above 9000C. Lower titanium bond strength was
attributed to a thick TiO2 on the metal surfaces when
titanium was oxidized at higher temperatures46. Menis
et. al47 attempted to bond low fusing porcelain to cast
titanium at approximately 8000C. Although the bond
strength was nominally comparable with the bond
strength of porcelain bonded to Ni-Cr alloy, separation
of porcelain from the cast titanium occurred at the oxidemetal interface.
Currently at least one system Procera ( Noble Biocare,
Gothenburg, Sweden) has had success in fabricating
single unit crowns and multiple unit bridges from
commercially pure wrought titanium. A compatible
low fusing porcelain, Ti-Ceram has been developed
for veneering these restorations. The advantage of
the Procera system over cast Ti is that it overcomes
the hardened surface layer that is encountered with
Ti castings, therefore providing adequate porcelain
titanium bonding1, 54, 55.
Boeing et al56 in an invitro study indicated that Procera
crowns had a good marginal fit, if a feather edge or
chamfer preparation is used. Marginal gaps range from
270 to 750 microns with shoulder preparation because of
the construction of the duplication milling machine. Their
results also showed that the Ti ceramic bond passed the
Deutsche Industrie Norm test but failed the International
Standards Organization test.
Togaya et al48. investigated the compatibility of porcelain
from the cast titanium and suggested that appropriate
bond strength between porcelain and titanium was
possible by reducing the thermal expansion coefficient
of the porcelain to approximate that of titanium.
Pang et al57 studied the bond strength of palladium
copper (Ney) to VMK68 (Vident), cast Ti to Duceratin
(Degussa) and machined milled Titanium to Procera.
The bond strength of palladium-copper to VMK68
porcelain was greater than that of the two Ti porcelain
combinations. There was no significant difference in the
bond strength of porcelain bonded or cast to machined
Ti. The multiple firing schedules did not significantly
affect the bond strength between low fusing porcelain
and grade2 Titanium.
Adachi et al49 evaluated the bonding of low fusing porcelain
to titanium and Ti-6Al-4V alloy by an x-ray spectrometric
technique. Oxide adherent strength values were
measured at 7500C and10000C via simulated porcelain
firings and actual porcelain application. The porcelain
delaminated completely from the metal substrate in
the constant flexural test, leaving less than 1% of the
surface covered with porcelain. The oxide adherence
of the specimen oxidized at 7500C was good; however
was too thin to be visualized in the scanning electron
microscope. Little or no residual stress due to thermal
mismatch should exist in the final titanium / porcelain
bond interface. The significant discrepancies already
noted in their thermal coefficients of expansion will have
to be more closely matched. An interfacial oxide layer
some 100 to 1000 microns thick, forms during firing and
the thicker this layer becomes, the weaker the bonding
between the porcelain and the titanium.
Nilson et al58 conducted a year clinical study on 44
Procera ceramic crowns and indicated that two crowns
had ceramic fracture, ratings for surface and color had
changed markedly from the excellent to the acceptable
level and anatomic form had a small shift from the
excellent to the acceptable level.
Further studies on clinical trial of Procera crowns
veneered with resin composites were performed by
Bergman et al59. Ten (5.2%) of 192 titanium crowns had
fractures of the resin composite veneer, but 99.5%of
the crowns were rated excellent or satisfactory. There
was a decrease from 83.4% to 70.1% in anatomic form
An enhanced titanium ceramic bond was reported when
porcelain was fired on cast titanium in a reduced argon
atmosphere50. An argon atmosphere limited the titanium
J. Nepal Dent. Assoc. (2009), Vol. 10, No.2
154
easier to laser weld titanium62. Short span multiple
bridges and bridges with pier abutments may be simple
to fabricate, since individual case units can be welded
together rather than being brazed. Since the bulk of the
titanium framework is unaffected by local heating, room
temperature assembly of appliances using accurate
casts can eliminate many factors where distortion might
be otherwise introduced.
and marginal integrity after 1 year of follow up. 96.8%
of the crowns showed excellent or satisfactory clinical
properties for their surfaces or colors. The authors
summarized that the initial marginal integrity was
satisfactory and remained so throughout the 2-year
follow up period.
Titanium as a dental implant material
Ossoeintegration has had a dramatic influence on
Prosthodontic practice. The best long term results
obtaining effective osseointegration have been produced
with commercially pure titanium (CPT). Another
material, Ti6Al4V which produces similar in vitro tissue
reactions as CPT has not produced as much clinical
success, probably though not conclusively due to leak
of aluminum ions that compete with calcium during early
stage of calcification2.
Yamagishi et al63 examined the mechanical properties
of Nd:YAG laser welds of titanium plates (1mm thick)
and found that there is a significant relationship
between three point bending strength and the irradiation
atmosphere, irradiation intensity and the combination
of atmosphere and intensity. Laser welding is effective
when performed in an argon atmosphere. Results vary
with various intensities of radiation.
Sjogren27 evaluated the tensile strength of welded
titanium rods and concluded that the penetration of laser
energy could be up to 0.9mm, leaving the central portion
of the rods unwelded. The welded specimens showed
different defects such as gas pores and cracks at the
fractured surfaces. The size and distribution of such
defects seemed to be dependent on the laser variables
used.
While titanium is the material of choice mainly on account
of its biocompatibility, its low modulus of elasticity, its
machinability into strong hollow tubes, and its potential
to be plasma sprayed or heat sintered in powder form
to create porous implant surface makes it a preferred
metal1. Modulus of Titanium is much closer to that of bone
than either stainless steel or Cobalt chromium, although
it is still five times that of cortical bone60. This property
leads to a more even distribution of stress at the critical
bone-implant interface, because bone and implant will
flex in a more similar fashion. Another classical way
to further make a device less stiff is to reduce cross
sectional area or to make it porous. Titanium lends
itself well to both these methods. It can be machined to
hollow and perforated designs and the implant surface
can be porous coated either by a plasma jet spraying it
with powder or by heat sintering Titanium or Titanium
alloy beads. Although there is some controversies
regarding optimal pore size, in general, openings of 100
micrometers or larger appear to permit bone in growth
and calcified bone ground substance may invade pores
in 1-10 micron size2. However if pores become too
large or too numerous, there is a danger of weakening
the coating to the point of mechanical instability. Also
porosity increases the exposed titanium surface area.
So even though the corrosion type reactions per unit
area are minimal, the significant increase in surface area
will increase the amount of reaction products61. Success
of dental implants would not only depend on the material
selection alone but also on the continual improvements in
the device design and clinical implantation techniques.
Berg et al64 evaluated the mechanical properties of laser
welded cast and wrought titanium base and compared
them to those of a brazed type IV cast gold alloy. No
significant difference in tensile strength was demonstrated
between cast and wrought titanium. When the ductility
of the Ti specimen was reduced the welded titanium
was found to be as strong as brazed gold, suggesting
that experimentally restorations made up of cast and
wrought titanium would satisfy clinical requirements.
Wang and Welsch65 compared three joining methods
for pure Ti and Ti6AlV alloys, using laser, tungsten inert
gas and infrared radiation and concluded that tungsten
inert gas method demonstrates overall better results in
terms of tensile strength and ductility, was also easy to
operate, and economically feasible. In this study lack of
complete joining was found among all the laser welded
samples, corroborating with similar results by Sjogren.
Summary
Selection of materials is based on a reconciliation of
their biocompatibility, optimum physical and mechanical
properties and where indicated their superior esthetic
qualities. A fundamental knowledge of the properties as
well as the limitations of dental materials is crucial, so
that the dentist can manipulate these materials to the
best benefit of the patient
Titanium Joining
Tungsten inert gas (Tig), laser beam welding and brazing
by infrared radiation heating techniques have been
used to join titanium metal in a protective environment.
Because of the low thermal conductivity of Titanium,
and greater rate of laser beam absorption makes it
Titanium and its alloys are known to have lightweight,
high strength to weight ratio, low modulus of elasticity
155
J. Nepal Dent. Assoc. (2009), Vol. 10, No.2
and excellent corrosion resistance. In addition it is
biocompatible and can be shaped and finished finding its
way into dental applications like implants and restorative
castings. Although more research is needed in areas
such as development of optimal casting investments,
porcelain veneering systems and controlled biological
responses its future use in dentistry appears very
bright.
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Journal of Nepal Dental Association (2009), Vol. 10, No. 2, Jul.-Dec., 158-161
Review Article
Management of obstructive sleep apnea using oral
appliances: A Review (Part I)
Kavitha PR1, P Vivek2, Bhat S3
Assistant Professor, Department of Orthodontic and Dentofacial Orthopedics, 3Professor, Vyas Dental College and Hospital, Jodhpur,
Rajasthan, 2Assistant Professor, Department of Pedodontics and Preventive Children Dentistry, A.B. Shetty Memorial Institute of Dental
Sciences
1
Abstract
Sleep-Disordered breathing (SDB) describes a group of disorders characterized by abnormalities of respiratory
pattern (pauses in breathing) or the quantity of ventilation during sleep. Obstructive sleep apnea (OSA) is one
of the commonest types of SDB, it is a condition characterized by the repetitive total or partial collapse of the
pharyngeal airway during sleep leading to oxygen desaturation or arousals.
The first part of our review tries to give an explanation of etiology, signs and symptoms, pathophysiology, diagnosis
and management of OSA. The second part focuses on the role of a dentist in treating OSA using various oral
appliances (OAs) and the dental changes brought about, side effects of appliances and patient compliance.
Key words: Sleep-disordered breathing (SDB), Obstructive sleep apnea (OSA)
Introduction
Obstructive sleep apnea (OSA) is a common upper air
way disorder characterized by repetitive, complete or
partial closure of the upper airway during sleep, resulting
in sleep fragmentation and oxygen desaturation, the
condition is also associated with loud snoring1,2. When
there is a cessation of airflow at the mouth and nose for 10
seconds or more, then such a condition is termed apnea
(Greek word ‘apnea’ means-without breath)3. During this
time, the individual's oxygen levels will drop. If a person
experiences 30 or more apneic episodes during a sevenhour sleep period, that person is believed to be suffering
from sleep apnea syndrome. These episodes can last
from 10 to 120 seconds. These apnea events terminate
with a partial awakening or an arousal. It is important to
understand that these arousals are necessary for the
person to begin breathing again4, as these arousals
increase the activity of tongue and throat muscles
that enlarge the airway5. OSA is a relatively common
condition occurring in 2 to 4% of males and 1 to 2 % of
females in middle age6. Though it can occur in any age,
the prevalence increases with the age. The problem is
even more common among obese people, with 40% of
men and 3% of women having the disorder6.
Pathophysiology
The underlying pathophysiology of OSA is complex and
not fully understood. The causes are multifactorial and
may vary considerably between individuals. Important
risk factors include obesity, male sex, and aging.
However, it is generally accepted that stability and
patency of the upper airway plays an important role3,7.
An obstruction in the upper airway can occur in three
areas. They are the nasopharyngeal, oropharyngeal,
and hypopharyngeal regions. The nasopharynx is the
part of the pharynx that lies above the level of the soft
palate. The oropharynx is the division of the pharynx
that lies between the soft palate and the upper edge
of the epiglottis. The hypopharynx is the division of the
pharynx that lies below the upper edge of the epiglottis
and opens into the larynx and esophagus4,8,9.
The upper airway obstruction during sleep may occur as
a result of narrowing of the respiratory passages. Partial
obstruction results in loud, irregular snoring sounds
caused by air rushing through the narrow passage
and stimulating the soft palate, uvula, throat walls and
tongue to vibrate. The narrower the airway passage,
Correspondence
Dr. Vivek P., Assistant Professor, Department of Paediatric and Preventive Children Dentistry, A.B. Shetty Memorial Institute of Dental
Sciences, Mangalore, India, E-mail: [email protected]
J. Nepal Dent. Assoc. (2009), Vol. 10, No.2
158
the greater the negative pressure. When the negative
pressure increases to a certain point, the airway may
completely collapse. This is what is known as an apneic
episode, during which breathing ceases7,8,10,11. The
apneic episode terminates in an arousal, which results
in increased muscle tone of the airway, opening up the
pharynx so breathing is re-established9.
Nocturnal symptoms include difficult breathing whilst
asleep, heavy snoring, gasping and choking, restless
sleep, heavy sweating, nightmares, frequent arousals
during sleep (fragmented sleep), kicking and leg
movements and bed wetting in children4,13,15,16,17.
Diagnosis
Medical diagnosis
Diagnosis can be made on history, examination,
polysomnography, split night testing and oximetry.13
The most reliable method to identify OSA is a nocturnal
polysomnograph The necessary parameters recorded
are: mobility of thoracic and abdominal muscles, cardiac
rate, ECG, air flow through nasal and oral cavities,
hemoglobin saturation in oxygen and exhaled carbon
dioxide4,10,13,15,19. A number of imaging modalities like
nasopharyngoscopy, fluoroscopy, MRI and computed
tomography have also been used to assess the
airway15.
Also it is been hypothesized that individuals with OSA
have impaired genioglossal function, allowing the
prolapse of tongue against the posterior pharyngeal wall
with inspiration effort during sleep3.
Etiology
The commonest cause of a narrow upper airway is
obesity7,12. One possible explanation for the relationship
between obesity and OSA is that the upper airway is
narrowed in obese patients as a result of increased
fat deposition in the pharyngeal walls7,12. In nonobese
individuals, craniofacial anomalies like micrognathia
and retrognathia resulting in insufficient room for the
tongue thus predisposing to OSA13,14. Other craniofacial
features predisposing to OSA include enlarged palatine
tonsils, enlarged uvula, high arched palate, deviated
nasal septum, long anterior facial height, inferiorly
displaced hyoid bone, macroglossia and decreased
posterior airway space13,14. In addition ethnic background,
genetics, habits such as alcohol consumption, smoking
and sedatives can aggravate the chances of OSA7,13.
Apnea severity is usually categorized by the frequency
of apnea events that occur per hour. The apneahypopnea index, or AHI—also known as the respiratory
disturbance index—is used by many clinicians to
confirm the diagnosis and quantify the illness severity.
The categories are as follows4:
The causes of Obstructive Sleep Apnea (OSA) are
discerned as follows15:
•
Mild -- 5 to 20 episodes per hour;
•
Moderate -- 20 to 40 episodes per hour; and
•
Severe -- 40 or more episodes per hour.
Dental diagnosis
A dentist may be the first health care provider to
identify a person with OSA because its salient signs
and symptoms often are recognizable in the dental
office10. Dental assessment includes history and oral
examination focusing on occlusion, periodontal status,
tooth mobility, parafunctional habits, TMJ evaluation,
wear facets, DMFT, recording sensitivity of teeth, tori,
and amount of over jet and overbite present.13 The
lateral cephalometric radiographs of people with OSA
usually show an elongated soft palate, a large tongue,
a retropositioned maxilla and mandible, an inferiorly
positioned hyoid bone, a narrowed posterior airway
space or calcified carotid artery atheromas10.
(a) Anatomic anomalies: such as hypertrophic tonsils
and adenoids, choanal atresia or stenosis, anomalies
of the nasal septum and soft tissue thickening of the
upper respiratory system.
(b) Neuromuscular diseases: such as cerebral palsy,
myotonic dystrophy, congenital myopathies. These
diseases may coexist with decreased muscle tone
of the upper respiratory muscles and defective
breathing control by the central nervous system.
(c) Craniofacial anomalies:such as midfacial hypoplasia,
micrognathia, hypotony, and sometimes mental
retardation.
Signs and Symptoms
OSA is associated with a series of daytime and
nocturnal signs and symptoms. The daytime symptoms
include excessive sleepiness and abnormal behavior
ranging from aggressiveness, hyperactivity and social
withdrawal. Morning headaches, poor job performance,
loss of alertness, clouded memory, intellectual
deterioration and occupational accidents are also some
presenting symptoms4,13,15,16,17.
Treatment modalities
Treatment of OSA is aimed at the reduction or eliminating
the collapse of pharyngeal tissues. Treatment for OSA
must be based on the assessment of severity of the
sleep disorder, patient’s preference and general health.
The treatment options must be less invasive whenever
possible. Simplest options are lifestyle modification
and oral appliance therapy for mild to moderate cases.
Continuous positive airway pressure and surgical
options are for moderate to severe cases11,13.
159
J. Nepal Dent. Assoc. (2009), Vol. 10, No.2
have been proposed by which drugs could reduce the
severity of OSA. These include an increase in tone
in the upper airway dilator muscles, an increase in
ventilatory drive, a reduction in the proportion of REM
sleep, a reduction in airway resistance and a reduction
in surface tension in the upper airway. Physostigmines,
nasal lubricant, topical nasal steroid, acetazolamide are
some of the drugs which are used21.
The treatment options can be non-surgical or surgical
based on the preference of the patient.
Non-surgical options
•
Lifestyle modification
1. Loose weight. People with severe sleep apnea
are often overweight. Loss of weight will result in
reduced adipose tissue volume in the upper airway,
decrease the load on the chest wall and abdomen,
and improve respiratory muscular efficiency4,12.
Surgical treatment
Surgery aims to alleviate anatomic sites of obstruction in
the naso-, oro-, and hypopharynx22. Surgical treatment
increases the upper airway cross-sectional area,
removes obstructive tissues, such as enlarged tonsils,
or bypass the pharyngeal airway23,24.
2. Sleep on one side. The patients who sleep on
their backs have a significantly higher level of
sleep disturbance as the supine position causes a
gravitational pull on the tongue forcing it to come in
contact with the posterior pharyngeal wall. Therefore,
any technique that allows one to sleep on a side
could be beneficial.4
The principal interventions can be considered as23:
1. Tracheostomy (which bypasses the pharyngeal
airway)
3. Avoid alcohol within two to three hours of
bedtime. Alcohol is a central nervous system
depressant and changes motor activity in the
muscles that control normal inspiration. These
changes include relaxation of the walls of the upper
airway causing it to collapse4.
2. Uvulopalatopharyngoplasty (UPPP) which increases
the area of the retro palatal airway by resection of
the free edge of the uvula and soft palate, and may
be combined with tonsillectomy- a modification is
laser-assisted uvulopalatoplasty (LAUP)
4. Avoid
certain
pharmacological
agents.
Benzodiazepines, narcotics, barbiturates, and
testosterone have all been reported to affect the
occurrence of apneic episodes4.
3. Tonsillectomy and adenoidectomy
treatment of OSA in children
accepted
4. Inferior sagittal mandibular osteotomy and
genioglossal advancement with hyoid myotomy and
suspension (GAHM) aims to create an enlarged
retrolingual airway.
Other life style modifications are designed to improve
‘sleep hygiene’. These include measures to improve the
sleep environment like to keep the bed comfortable and
the bedroom warm, quiet and dark, avoiding caffeinated
drinks in the evenings and avoiding daytime napping12.
5. Laser midline glossectomy and lingualplasty also
create an enlarged retrolingual airway.
6. Maxillo-mandibular osteotomy and advancement
enlarges both retrolingual and retropalatal airway.
Medical treatment
7. Epiglottoplasty
laryngomalacia.
1. Nasal Continuous Positive Airway Pressure
The gold standard treatment for OSA is nasal continuous
positive airway pressure (nCPAP) delivered via a nasal
mask. This technique involves wearing a mask tightly
over the nose during sleep. A high flow blower delivers
a continuous stream of air into a sealed nasal mask.
This forced air creates a pneumatic splint, keeping the
airway open and allowing the person to sleep normally.
This is a highly effective therapy and is the most
common approach for moderate and severe apnea
patients4,8,10,21. Unfortunately, compliance with nCPAP
has been very poor. nCPAP has its own side effects
such as claustrophobia, air leaks, pressure sores, nasal
stuffiness, dry mouth, and mask discomfort8,10,20.
for
selected
cases
of
8. Removal of local specific obstructing pathological
lesions.
Surgical success depends on appropriate patient
selection, the type of procedure performed, and the
experience of the surgeon. Surgery is considered
appropriate on a case-by-case basis in patients with
usually moderate to severe OSA with associated
symptoms of excessive daytime sleepiness or with
significant medical morbidities22.
Untreated OSA can result in serious morbidity8.
Cardiovascular disease is common in patients with
OSA. The prevalence of angina, cardiac arrhythmias
and myocardial infarction is increased in patients with
apnea8,18. Cerebrovascular diseases may also be more
prevalent in these patients8,18. There are metabolic and
other systemic complications that also may occur as a
result of untreated sleep apneas18.
2. Drug therapy
Drug therapy has been proposed in some patients with
mild to moderate sleep apnea and could be of value in
patients intolerant to nCPAP. A number of mechanisms
J. Nepal Dent. Assoc. (2009), Vol. 10, No.2
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160
Conclusion
Obstructive sleep apnea (OSA) is a common upper air
way disorder characterized by repetitive, complete or
partial closure of the upper airway during sleep, resulting
in sleep fragmentation and oxygen desaturation, the
condition is also associated with loud snoring. In this
first part the authors have reviewed the etiology, signs
and symptoms, diagnosis and treatment modalities in
offer and the following second part reviews on the role of
a dentist in the treatment perspective of OSA.
13.
Padma A, Ramakrishnan. N, Narayanan V. Management
of obstructive sleep apnea: A dental perspective. Indian J
Dent Res. 2007; 18:4: 201-209.
14.
Solow B, Skov S, Ovesen J, Norup P, Wildschiodtz G.
Airway dimensions and head posture in obstructive sleep
apnea. Eur J Ortho.1996; 18: 571-579.
15.
Papazoglou K, Papagrigorakis MJ. Sleep apnea in
children. Hell Orthod Rev 2004; 7:33-43.
16.
Carvalho FR, Lentini-Oliveira DA, Machado MAC,
Saconato H, Prado LBF, Prado GF. Oral appliances and
functional orthopaedic appliances for obstructive sleep
apnea in children. Cochrane Database of Systematic
Reviews 2007, 2:CD005520. DOI: 10.1002/14651858.
CD005520.pub2.
17.
Joshi AS, Steven A, Bielamowicz SA, Alexander AAZ,
Truelson M, Roberts DH. Snoring and Obstructive Sleep
Apnea, Prosthetic Management. eMedicine Specialties:
Jun 28, 2007. Available from http://emedicine.medscape.
com/article/870192-diagnosis.
18.
Simmons MS, Clark GT. The potentially harmful medical
consequences of untreated sleep-disordered breathing.
The evidence supporting brain damage. J Am Dent
Assoc. 2009; 140: 5:536-542.
19.
Pae EK, Lowe AA, Sasaki L, Price C, Tsuchiya M, Fleetham
JA. A cephalometric and electromyographic study of upper
airway structures in the upright and supine position. Am J
Orthod Dentofac Orthop. 1994; 106: 52–59.
20.
Chai CL, Pathinathan A, Smith B. Continuous positive
airway pressure delivery interfaces for obstructive sleep
apnea. Cochrane Database of Systematic Reviews 2006;
4:CD005308. DOI: 10.1002/14651858.CD005308.pub2.
21.
Smith I, Lasserson TJ, Wright JJ. Drug therapy for
obstructive sleep apnea in adults. Cochrane Database
of Systematic Reviews 2006; 2: CD003002. DOI:
10.1002/14651858.CD003002.pub2.
22.
Won CHJ, Li KK, and Guilleminault C. Surgical Treatment
of Obstructive Sleep Apnea - Upper Airway and
Maxillomandibular Surgery. Proc Am Thorac Soc. 2008;
5: 193–199.
23.
Sundaram S, Lim J, Lasserson TJ. Surgery for obstructive
sleep apnea in adults. Cochrane Database of Systematic
Reviews 2005; 4: CD001004. DOI: 10.1002/14651858.
CD001004.pub2.
24.
Lim J, McKean MC. Adenotonsillectomy for obstructive
sleep apnea in children. Cochrane Database of Systematic
Reviews 2009; 2: CD003136. DOI: 10.1002/14651858.
CD003136.pub2.
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Journal of Nepal Dental Association (2009), Vol. 10, No. 2, Jul.-Dec., 162-165
Review Article
Management of obstructive sleep apnea using oral
appliances: A Review (Part II)
Kavitha PR1, P Vivek2, Bhat S3
Assistant Professor, Department of Orthodontic and Dentofacial Orthopedics, 3Professor, Vyas Dental College and Hospital, Jodhpur,
Rajasthan, 2Assistant Professor, Department of Pedodontics and Preventive Children Dentistry, A.B. Shetty Memorial Institute of Dental
Sciences
1
Abstract
There are various treatment options for obstructive sleep apnea (OSA) ranging from simple lifestyle modifications
to surgical options. Some treatments are cumbersome in nature which makes tolerance and compliance less than
optimal. This gives rise to the need for other alternatives that are equally effective and more tolerable. Dentists
play a vital role in the treatment of OSA. There is growing interest in the use of oral appliances (OAs) to treat OSA.
Wide ranges of appliances are available and are well tolerated by the patients. This second part of our review
article focuses on various appliances their mechanism of action and effects on oral cavity.
Key words: Oral appliances (OAs), Dental appliances, Mandibular advancement appliances (MADs), Obstructive
sleep apnea (OSA)
Introduction
Dentists have recently begun to play a role in the
management of obstructive sleep apnea (OSA) with the
use of various oral appliances (OAs) or dental appliances.
These appliances can reposition the tissues by lifting up
the soft palate, bringing the tongue forward, or lifting
the hyoid bone. As they reposition, some appliances
also stabilize these tissues, preventing airway collapse.
Appliances can also increase muscle tone. Specifically,
there is an increase in pharyngeal and genioglossus
muscle activity1.
Historical aspects of oral appliances
George Cattlin was probably the first person who
seriously thought that the route of breathing may influence
sleep quality and daytime function5. He pointed out that
breathing through the nose promotes more restful and
better quality sleep, which translates into better daytime
function and better general health. However, modern
published clinical work began in 1903, when Pierre Robin
first described a device, called the “monoblock”, for the
treatment of glossoptosis. It took almost another 50
years to start using oral appliances for the treatment of
snoring and sleep apnea when Cartwright and Samelson
described the tongue retaining device in 1982. This work
stimulated further investigations5.
These appliances are usually inexpensive, well tolerated
by the patients and the side effects if any are thought to
be reversible2. There are a large and diverse designs that
have been used in clinical practice and research studies.
It is important to consider these design features when
choosing a device, as they may influence the retention
of the oral appliance within the oral cavity during sleep,
the degree of advancement of the mandible, and the
range of movement of the mandible that is permitted. As
a result, variations in design may affect clinical efficacy,
adverse effects, and patient compliance3,4.
Types of oral appliances
There are abundant variety of appliances available
and all these oral appliances may be divided into
three general groups: soft palate lifters (SPLs), tongue
retaining devices (TRDs), and mandibular advancement
devices (MADs) also known as mandibular advancement
appliances (MAA) or mandibular advancement splints26.
Correspondence
Dr. Vivek P., Assistant Professor, Department of Paediatric and Preventive Children Dentistry, A.B. Shetty Memorial Institute of Dental
Sciences, Mangalore, India, E-mail: [email protected]
J. Nepal Dent. Assoc. (2009), Vol. 10, No.2
162
The first category is virtually no longer in use today most
likely because of gag, discomfort, and the success of
laser and radio frequency soft-palate procedures. The
second category is used very seldom, mainly if there are
dental reasons precluding the fabrication of MAD. The
last category (MAD) is by far the most common type of
dental appliance in use today. It protrudes the mandible
forward, thus preventing or minimizing upper airway
collapse during sleep5,6.
Tongue retaining devices (TRDs) is a custom made
soft acrylic appliance that has an anterior plastic bulb.
It uses negative suction pressure to hold the tongue in
forward position inside the bulb. By holding the tongue
in forward direction through its attachment to genial
tubercle, it stabilizes the mandible and hyoid bone, thus
preventing the retrolapse of tongue10.
Effects of oral appliances
The goals of treatment with oral appliances are to
prevent obstructive apneas and hypopneas during sleep,
to improve the symptoms of OSA (such as snoring,
excessive daytime sleepiness, and neurocognitive
impairment), and to decrease the cardiovascular risk
associated with OSA3.
Design and mechanism of action
There are various designs of oral appliances that have
been used in clinical practice and research studies.
Fabrication of appliance requires dental impressions,
bite registration and fabrication by dental laboratory.
However, they can be prefabricated too. The mandibular
advancers may be made of elastomeric material or hard
acrylic, or thermoplastic. Their retention on the teeth can
be provided by friction fit of plastic in undercuts, which is
most common, or by clasps7.
Approximately 65% of patients achieve a 50% or greater
reduction in apnea–hypopnea index (AHI) with MAD.
Treatment with an MAD also improves oxyhemoglobin
saturation. Improvements in sleep architecture and
reduction of arousal indices have also been shown.
There is significant reduction in the intensity and
frequency of snoring. MAD may have a positive impact
on cardiovascular disease, with improvement of
intermediate end points such as oxidative stress and
endothelial function3.
Mandibular advancement appliances are either onepiece (monobloc) or twopiece (duobloc) configuration3.
The former may be a simple vacuum formed splints
with upper and lower fused together or clasped acrylic
appliances, for example snore-guard, SNOAR etc. Two
piece splints, where upper and lower elements are
connected by rigid or plastic lateral connectors, allow
some freedom of mandibular movement, for example
Silencer, Herbst, Restore4,8.
It is clear that not all patients are able to achieve a
successful treatment outcome with oral appliances.
There are anthropomorphic, physiological, and
polysomnographic parameters that have been
associated with a better treatment outcome, these
parameters include female sex, lower age, lower body
mass index, the amount of mandibular protrusion,
smaller neck circumference, lower baseline AHI, supinedependent OSA, and primary oropharyngeal collapse of
the upper airway during sleep3,6.
The primary mechanism of action of MADs is to
cause mechanical advancement of the mandible and
thereby increase the anteroposterior dimensions of
the oropharynx. Mandibular advancement appliances
are constructed so that the mandible is positioned
2 to 5 millimeters anteriorly. The amount of forward
repositioning and vertical opening varies with the
appliance, the clinician and also the comfort on part
of the patient. The tongue is also advanced passively
because of its attachment to the genial tubercles. These
devices simultaneously move the soft palate anteriorly
because of its attachment to the tongue via the
palatoglossus muscle. These movements enlarge the
hypopharyngeal airway and reduce the likelihood that
the tongue or soft palate collapse against the posterior
pharyngeal wall when the patient inspires during sleep9.
The precise reason for this effect on hypopharyngeal
patency is unclear. However, soft tissue connections
exist between the mandible, tongue, lateral pharyngeal
walls, and soft palate, within the palatoglossal and
palatopharyngeal arches. It has been proposed that such
soft tissue connections may be stretched by mandibular
advancement3,5,10.
Factors affecting the success of oral appliances
(OAs)8,11
1. Retentive factor - OAs must fit accurately, comfortably,
and remain in position all night.
2. OAs should be able to variably adjust mandibular
position. Appliance should provide lateral movement
for the mandible.
3.
The appliance must be of low bulk. The absence
of bulk makes an appliance more comfortable and
therefore more likely to be worn.
4. Appliances that allow the lips to close are more likely
to be accepted by patients and are easier to get used
to.
5. Appliances that pinch the lips or have protuberances
into or beyond the lips and appliances made at
excessive vertical opening, the compliance will be
poor.
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produce the clinical syndrome of OSA. Different factors
will predominate in individual patients, but it is likely
that all patients with clinically significant OSA have a
multifactorial aetiology, rather than any single causative
factor. However, these factors, such as defects in
ventilatory control and protective upper airway reflexes,
are less easily defined and further research is needed to
elucidate their precise role in maintaining upper airway
patency during sleep4,7.
6. Appliances should be non-interfering with sleep.
Many appliances may cause awakening either owing
to its being bulky or as a result of violation of lip seal
or tongue space.
7. Must be economical.
Indications and contraindications
OAs are indicated for patients with the following11:
•
Simple snoring problems.
•
Mild to moderate OSA
A better understanding of the interacting factors that
lead to the development of clinically significant OSA will,
hopefully, lead to the development of simpler modalities
of therapy10.
OAs are contraindicated for patients with the following11
•
Active dental disease
•
Minimal protrusive range
•
Children
•
Acute temporomandibular joint dysfunction (TMJD)
symptoms.
•
TMJ arthritis
•
Obvious psychological aversion to structures in the
oral cavity
•
Moderately limited dexterity
Oral appliances have proved to be vital as a treatment
modality for OSA, future studies are needed to evaluate
the effect of different appliance designs upon the
success rate for reducing the AHI and improving sleep
and symptoms6. Standard AHI criteria for success
should be established as well as standard protocols
for follow-up and documenting adverse effects.7
Future comparisons of OAs to nCPAP therapy may
provide different results from studies done several
years ago because of improvements in both modalities
of therapy. Objective measurements of snoring and
treatment adherence should also be obtained.9 Ongoing
refinements of appliance design may eventually lead to
improved outcomes with fewer complications. Head to
head comparisons of different appliances and different
design features may provide more information as to
the key design elements that are related to treatment
efficacy, adherence and complications. The role of
these appliances, particularly MAD, in adolescents and
children has yet to be evaluated in a comprehensive or
systematic way. Studies addressing these issues will
advance the field of OAs therapy and improve the care
being delivered to patients with OSA8.
Disadvantages of oral appliances6,11
The advancement of the mandible or tongue, being the
principal mechanism of action of oral appliances, has
the potential to cause adverse effects too. Mandibular
advancement splints generate reciprocal forces on the
teeth and jaw that can result in acute symptoms, as well
as long-term dental and skeletal changes.
Short-term adverse effects6,11
•
Excessive salivation
•
Mouth dryness
•
Tooth pain
•
Gingival and oral mucosal irritation
•
Headaches
•
Temporomandibular joint discomfort
•
Mouth sores
•
Periodontal complications
•
Ingestion of broken appliance
Conclusion
Major advances in the field of oral appliances have
provided evidence for the use of oral appliances in the
clinical management of OSA. These developments have
been reflected in the updated practice parameters which
now recommend the use of oral appliances for mild-tomoderate OSA, or for patients with severe OSA who
are unable to tolerate nCPAP or refuse treatment with
nCPAP.
Long-term adverse effects6,11
•
Reduction in overjet
•
Increase in facial height
•
Increase in degree of mouth opening
•
Changes in inclination of incisors
•
Increase in mandibular plane angle
•
Root resorption
As a simpler alternative to nCPAP, oral appliances
are often regarded by patients as a more acceptable
treatment option for OSA. This has the potential to
translate to better treatment adherence and equivalent
health benefits, despite the lower efficacy of oral
appliances compared to nCPAP. Future research should
focus on determining the influence of the design of
Discussion
Various factors, ranging from upper airway anatomy
to central respiratory control mechanisms, interact to
J. Nepal Dent. Assoc. (2009), Vol. 10, No.2
164
oral appliances on clinical outcome, the development
of a clinically reliable method for identifying those
patients who are most likely to achieve a favorable
treatment response, and the characterization of factors
predisposing to long-term adverse effects of oral
appliance treatment.
5.
Hoffstein V. Review of oral appliances for treatment of
sleep-disordered breathing. Sleep Breath.2007; 11:1–22.
6.
Chan ASL, Lee RWW, Cistulli PA. Dental appliance
treatment for obstructive sleep apnea. Chest. 2007;
132:693–699.
7.
Wolfgang S, Alan L,Laurel W, Rosalind C, Francisco C,
Stuart M. Oral appliances for treatment of snoring and
obstructive sleep apnea. A review. Sleep. 1995; 18(6):
501- 510.
8.
James EE. Comparison of oral devices for snoring. J Calif
Dental Assoc. 1998.August.
9.
Friedlander AH et al., Diagnosing and Co managing
patients with obstructive sleep apnea syndrome. J Am
Dent Assoc. 2000; 131:1179- 1184.
10.
Padma A, Ramakrishnan. N, Narayanan V. Management
of obstructive sleep apnea: A dental perspective. Indian J
Dent Res. 2007; 18(4): 201-209.
11.
Joshi AS, Steven A, Bielamowicz SA, Alexander AAZ,
Truelson M, Roberts DH. Snoring and Obstructive Sleep
Apnea- Prosthetic Management. eMedicine Specialties:
Jun28,2007. Available from http://emedicine.medscape.
com/article/870192-diagnosis.
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Veis R.W. Snoring and Obstructive Sleep Apnea from a
Dental Perspective. J Calif Dental Assoc.1998.August.
Johnston CD, Gleadhill IC, Cinnamond MJ, Peden MW.
Oral appliances for the management of severe snoring:
A randomized controlled trial. Eur J Ortho.2001:23; 127134.
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Chan ASL, Lee RWW, Cistulli PA. Non–Positive Airway
Pressure Modalities- Mandibular Advancement Devices/
Positional Therapy. Proc Am Thorac Soc.2008; 5: 179–
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Tan YK et al., Mandibular advancement splints and
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obstructive sleep apnea: A randomized crossover trial.
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