1. health and fitness
2. disease

Welcome Message
On behalf of the Local Organizing Committee, we are pleased to welcome you to the 4th
Tri-University Consortium on Oral Science and Education in Bangkok, Thailand on 20 – 21 May
2015. This conference continues the collaboration among the three sister universities, Chulalongkorn
University, Peking University, and Tokyo Medical and Dental University and provides an
opportunity for administrative teams from each university to meet and exchange ideas and visions
for the future. The scientific program draws keynote speakers together with many young researchers from various disciplines, including an outstanding PhD student from each school, to present
their latest research work. Moreover, the poster session is an opportunity for researchers who wish
to share their recent research findings.
The 4th Tri-University Consortium on Oral Science and Education provides an outstanding
forum for participants from the three dental schools to become better acquainted and to learn
about the directions of each other’s research and educational programs. This is also an excellent
opportunity to share the most up-to-date information concerning oral science research, and to
meet and interact with leading scientists from each dental school. Presentations from the Deans,
keynote speakers, and oral and poster presentations will provide delegates with information on
the latest developments in both basic science and the clinical application of research from each
dental school. Young investigators’ sessions, including PhD students from each school, will cover
an array of topics in which each university excels.
To complement the rigorous scientific program, delegates will have the opportunity to relax
and enjoy Thai cultural performances presented by Chulalongkorn University dental students, and
dine on many varieties of delicious Thai cuisine.
We wish you a hearty welcome to Chulalongkorn University, Bangkok, Thailand, and we
all look forward to enjoying each other’s company at the welcome reception.
Assistant Professor Suchit Poolthong
Dean of the Faculty of Dentistry, Chulalongkorn University
The 4th Tri-University Consortium
Schedule on Wednesday May 20th, 2015
Faculty of Dentistry, Chulalongkorn University
08.00 - 08.30 Registration
08.30 - 09.00 Opening address
Dean of the Faculty of Dentistry, Chulalongkorn University
09.00 - 09.20 O-1 Congratulations for the 4th Tri-University Consortium and Looking Forward to
More Fruitful Collaborations in the Future
Professor Chuanbin Guo
Dean of the Peking University School of Stomatology, Beijing, China
09.20 - 09.40 O-2 TMDU Faculty of Dentistry, Cultivating Professionals with Knowledge and
Humanity, thereby Contributing to People’s Well-Being
Professor Keiji Moriyama
Dean of the Faculty of Dentistry, Tokyo Medical and Dental University, Tokyo, Japan
09.40 - 10.00 O-3 Curriculum Reform for AEC Preparation: Are We on the Right Track?
Assistant Professor Suchit Poolthong
Dean of the Faculty of Dentistry, Chulalongkorn University, Bangkok, Thailand
10.00 - 10.30 Coffee Break
Research Highlights
10.30 - 11.00 O-4 The State of the Art of Bone Tissue Engineering-----New Approaches for
Oral Maxillofacial Rehabilitation and Implant Dentistry
Professor Yongsheng Zhou (Peking University)
11.00 - 11.30 O-5 Recent Challenges in Mechanical Stress Analyses for Optimization of Restorative
and Prosthodontic Biomaterials
Professor Noriyuki Wakabayashi (Tokyo Medical and Dental University)
11.30 - 12.00 O-6 Chitosan as an Antifungal Agent: Mechanisms and Applications in Dentistry
Associate Professor Oranart Matangkasombut (Chulalongkorn University)
12.00 - 13.30 Lunch
Clinical Research
13.30 - 13.55 O-7 Application of Synchrotron Radiation X-ray for the Clinical Diagnosis
Professor Motohiro Uo (Tokyo Medical and Dental University)
13.55 - 14.20 O-8 Comparative Histological Study in Maxillary Sinus Augmentation Using
Coarse or Fine Particle of Xenograft Materials (Preliminary Report)
Dr. Paksinee Kamolratanakul (Chulalongkorn University)
14.20 - 14.45 O-9 Basic Study Focused on Fitting Accuracy of Thermoplastic Resin for non-metal
Clasp Denture
Assistant Professor Junichiro Wada (Tokyo Medical and Dental University)
Basic Science Research I
14.45 - 15.10 O-10 Effects of Compatibility of Deproteinized Antler Cancellous Bone with
Various Bioactive Factors on Their Osteogenic Potential
Dr. Yan Wei (Peking University)
15.10 - 15.35 O-11 Targeted Deletion of Cathepsin K in the Osteoclast Lineage Couples Bone
Resorption to Formation through S1P-dependent Mechanism
Dr. Sutada Lotinun (Chulalongkorn University)
15.35 - 16.00 O-12 Immunohistochemical and Gene-expression Analysis of Pulp Injury-induced
Glial Cell Activation in the Rat Thalamus
Assistant Professor Jun Kawamura (Tokyo Medical and Dental University)
16.00 - 16.30 Coffee Break
16.30 - 17.30 Poster Presentation
The 4th Tri-University Consortium
Schedule on Thursday May 21st, 2015
Faculty of Dentistry, Chulalongkorn University
Basic Science Research II
08.30 - 08.55 O-13 In vitro Cytotoxicity of Mussel-Mimetic Bio-adhesive Polymers in Comparison
with Conventional Dental Materials
Assistant Professor Noriko Hiraishi (Tokyo Medical and Dental University)
08.55 - 9.20
O-14 The Development of Prostacyclin Drug Delivery System for Bone and
Tooth Regeneration
Dr. Chalida Nakalekha Limjeerajarus (Chulalongkorn University)
09.20 - 09.45 O-15 The Effects and Epigenetic Mechanisms of TiO2 Nanotubes on the Osteogenic
Differentiation of Human Adipose-derived Stem Cells
Dr. Longwei Lv (Peking University)
09.45 - 10.10 O-16 Improvement of Bonding Between Veneering Porcelain and Zirconia
Substructure with Glass Ceramic Liner
Dr. Kamolporn Wattanasirmkit (Chulalongkorn University)
10.10 - 10.40 MOU Signing Ceremony
10.40 - 10.55 Coffee Break
10.55 - 11.20 O-17 Establishment of Occlusion in a Virtual Environment: Workflow and Accuracy
Dr. Xiaojing Liu (Peking University)
11.20 - 11.45 O-18 miR-29b Suppresses Proliferation, Migration, and Invasion of Tongue Squamous
Cell Carcinoma through PTEN-AKT Signaling Pathway by Targeting Sp1
Dr. Lingfei Jia (Peking University)
Research by PhD students
11.45 - 12.05 O-20 Tooth Regenerative Therapy by Utilizing a Split Tooth Germ
Dr. Naomi Yamamoto (Tokyo Medical and Dental University)
12.05 - 12.25 O-21 Rinsing with Saline Promotes Gingival Fibroblast Wound Healing in Vitro
Dr. Nam Cong-Nhat Huynh (Chulalongkorn University)
12.25 - 12.45 O-19 Integrated Profiling of mRNAs and microRNAs to Identify Potential
Biomarkers for Oral Malignant Transformation
Dr. Wen Shi (Peking University)
12.45 - 14.00 Lunch
18.00
Welcome Reception
Table of Contents
Pages
Message from Dean
The 4th Tri-University Consortium Program
Oral Presentation
O-1 Congratulations for the 4th Tri-University Consortium and Looking Forward to More
Fruitful Collaborations in the Future
2
O-2 TMDU Faculty of Dentistry, Cultivating Professionals with Knowledge and Humanity,
thereby Contributing to People’s Well-Being
3
O-3 Curriculum Reform for AEC Preparation: Are We on the Right Track?
4
Research Highlights
O-4 The State of the Art of Bone Tissue Engineering-----New Approaches for Oral Maxillofacial 6
Rehabilitation and Implant Dentistry
O-5 Recent Challenges in Mechanical Stress Analyses for Optimization of Restorative and
Prosthodontic Biomaterials
7
O-6 Chitosan as an Antifungal Agent: Mechanisms and Applications in Dentistry
8
Clinical Research
O-7 Application of Synchrotron Radiation X-ray for the Clinical Diagnosis
10
O-8 Comparative Histological Study in Maxillary Sinus Augmentation Using Coarse or
Fine Particle of Xenograft Materials (Preliminary Report)
11
O-9 Basic Study Focused on Fitting Accuracy of Thermoplastic Resin for Non-metal Clasp
Denture
12
Table of Contents
Page
Basic Science Researches I
O-10 Effects of Compatibility of Deproteinized Antler Cancellous Bone with Various 14
Bioactive Factors on Their Osteogenic Potential
O-11 Targeted Deletion of Cathepsin K in the Osteoclast Lineage Couples Bone Resorption
to Formation through S1P-dependent Mechanism
15
O-12 Immunohistochemical and Gene-expression Analysis of Pulp Injury-induced Glial Cell
Activation in the Rat Thalamus
16
Basic Science Researches II
O-13 In Vitro Cytotoxicity of Mussel-Mimetic Bio-adhesive Polymers in Comparison with
Conventional Dental Materials
18
O-14 The Development of Prostacyclin Drug Delivery System for Bone and Tooth Regeneration
19
O-15 The Effects and Epigenetic Mechanisms of TiO2 Nanotubes on the Osteogenic
Differentiation of Human Adipose-derived Stem Cells
20
O-16 Lithium Disilicate Glass-ceramic Liner Increases the Shear Bond Strength Between
Feldspathic Porcelain and Zirconium Oxide
21
O-17 Establishment of Occlusion in a Virtual Environment: Workflow and Accuracy
22
O-18 miR-29b Suppresses Proliferation, Migration, and Invasion of Tongue Squamous Cell
Carcinoma through PTEN-AKT Signaling Pathway by Targeting Sp1
23
Research by PhD students
O-19 Integrated Profiling of mRNAs and microRNAs to Identify Potential Biomarkers for
Oral Malignant Transformation
25
O-20 Tooth Regenerative Therapy by Utilizing a Split Tooth Germ
26
O-21 Rinsing with Saline Promotes Gingival Fibroblast Wound Healing in Vitro
27
Table of Contents
Page
Poster presentation Group 1 P1-P10
P-1 Thrombospondin-1 Expression by Periodontal Pathogen via Toll-like Receptor 2
(16.30 - 16.35)
29
P-2 Hierarchical Intrafibrillarly-mineralized Collagen Scaffolds for Mandible Regeneration
(16.35 - 16.40)
30
P-3 Effect of Aloe Vera on Oral Pathogens in Healthy Volunteers (16.40 - 16.45)
31
P-4 Infection of a Periodontal Pathogen, Porphyromonas gingivalis, Triggers Cardiac
Rupture of Infarcted Myocardium in Mice (16.45 - 16.50)
32
P-5 Transcriptomic Alteration of Cultured Dental Mesenchymal Cells (16.50 - 16.55)
33
P-6 In-office Bleaching Gel with 35% Hydrogen Peroxide Enhanced Biofilm Formation of
Early Colonizing Streptococci on Human Enamel (16.55 - 17.00)
34
P-7 Elevated Platelet Activation in Generalized Aggressive Periodontitis (17.00 - 17.05)
35
P-8 Human Cementoblasts Response to IL-1beta (17.05 - 17.10)
36
P-9 Denture Stability of Mandibular Implant Overdentures with Locator Attachments
(17.10 - 17.15)
37
P-10 Disparities in Tooth Loss and Prostheses Obtaining Among Thai Elderly
(17.15 - 17.20)
38
Poster presentation Group 2 P11-P21
P-11 Oculofaciocardiodental Syndrome: Novel BCOR Mutations and Expression in Dental
Cells (16.30 - 16.35)
40
P-12 Mutations in the PAX9 Gene Associated with Non-syndromic Oligodontia
(16.35 - 16.40)
41
P-13 Exome Sequencing Identified a Novel PCCB Mutation in a Thai Patient with Propionic
Acidemia (16.40 - 16.45)
42
P-14 New DLX3 Mutation Delays Senescence in Tricho-Dento-Osseous syndrome
(16.45 - 16.50)
43
P-15 A Retrospective Study of Jaw Cysts in Thai Population (16.50 - 16.55)
44
Table of Contents
Page
P-16 Exosomal TGFBI Promote Cervical Metastasis in OSCC Patients (16.55 - 17.00)
45
P-17 Underestimated PTCH1 Mutation Rate in Sporadic Keratocystic Odontogenic Tumors 46
(17.00 - 17.05)
P-18 Long-term Stability of Cutaneous and Muscle Pain Measures in Females (17.05 - 17.10)
47
P-19 Dose Sarcopenia Affect the Strength of Tongue Muscle and Supra Hyoid Muscle?
(17.10 - 17.15)
48
P-20 Progesterone Attenuates Hyperalgesia of Inflamed TMJ through Modulating Voltage-gated 49
Sodium Channel 1.7 in Trigeminal Ganglion (17.15 - 17.20)
P-21 Comparison Effects of Inflammation on Iodoacetate-induced Osteoarthritis in TMJ 50
and Knee Joint (17.20 - 17.25)
Poster presentation Group 3 P22-P32
P-22 Evaluation of the Shear Bond Strength of Dental Porcelain to Zr–14Nb Alloy with
Low Magnetic Susceptibility (16.30 - 16.35)
52
P-23 Silica Coating for Acrylic Denture Base Materials: The Effect of Solid Content 53
Concentration for Durability of Coating Layer (16.35 - 16.40)
P-24 Three-five Minutes Ultrasonic Cleaning Reduce Residual Monomer in Acrylic Resins
(16.40 - 16.45)
54
P-25 Effects of Surface Pre-reacted Glass-ionomer Fillers Contained Toothpastes on Inhibition
of Enamel Demineralization (16.45 - 16.50)
55
P-26 Wear Evaluation of Composite Resin and Antagonistic Tooth Enamel with Using Focus
Variation 3D Scanning Microscope (16.50 - 16.55)
56
P-27 Comparison of Mandibular Bone Micro-architecture Between MicroCT and 57
Cone-beam CT Images (16.55 - 17.00)
P-28 Detection of Apical Periodontitis using Cone-Beam Computed Tomography and
Periapical Radiography (17.00 - 17.05)
58
P-29 Effect of Exposure Parameters and Voxel Size on Bone Structure Analysis in
Cone-beam CT (17.05 - 17.10)
59
Table of Contents
Page
P-30 Observation of Cervical Demineralization Induced by Streptococcus Mutans Using
SS-OCT (17.10 - 17.15)
60
P-31 Correlation Among Pharyngeal Airway Dimension and Position and Dimension of
Surrounding Structures in Growing Thai Orthodontic Patients with Normodivergent
Facial Pattern (17.15 - 17.20)
61
P-32 Monitoring of Cariogenic Demineralization at Adhesive Interface Using SS-OCT
(17.20 - 17.25)
62
Oral Presentation
MAY 20th-21st, 2015
TRI-UNIVERSITY CONSORTIUM
O-1
Congratulations for the 4th Tri-University Consortium and Looking Forward to
More Fruitful Collaborations in the Future
Chuanbin Guo
Dean of the Peking University School of Stomatology, Beijing, China
On behalf of Peking University School of Stomatology (PKUSS), it is a great pleasure to take
part in the 4th Tri-University Consortium. I would like to express my sincere congratulation to the
consortium and heartful appreciation to everyone who made great effort in hosting the event. Since
the corporation agreement was signed in 2010, Tri-University Consortium has been an important
platform for young dental professionals to become better acquainted with each other, exchange
academic ideas and seek opportunities for cooperation, which have great significance to dental
research and education to the three distinguished dental schools, even to the development of
stomatology in Thailand, Japan and China.
PKUSS has always been the national key stomatological institutions clinically, academically and
educationally since its establishment. As one of the largest dental hospital, we successively ranked
the first place in the competition of stomatological hospitals nationwide, serving more than 4,000
outpatients per day. As an outstanding dental school, we provided a broad-spectrum dental and
medical education for students, home and abroad, with a series of training programs. Also as the
national key research institutions, we have been granted as “National Engineering Laboratory for
Digital and Material Technology of Stomatology” four years ago and “Beijing Key Laboratory
of Digital Oral Medicine” last month based on the plentiful academic achievements. PKUSS has
been attaching growing importance to international cooperation from one generation to another.
We have created cooperative relationships with more than 30 dental schools and institutions from
all over the world and was approved as the first international research base in stomatology schools
three years ago. Taking this consortium and the new MOU as an opportunity, we are looking
forward to more fruitful collaborations in the future. Finally, I wish the “The 4th Tri-University
Consortium on Oral Science and Education” great success!
2
TRI-UNIVERSITY CONSORTIUM
MAY 20th-21st, 2015
O-2
TMDU Faculty of Dentistry, Cultivating Professionals with Knowledge and
Humanity, thereby Contributing to People’s Well-Being
Keiji Moriyama
Dean of the Faculty of Dentistry, Tokyo Medical and Dental University, Tokyo, Japan
Tokyo Medical and Dental University (TMDU) is located in the Yushima / Shoheizaka area of
Tokyo, Japan, which is considered the sacred birthplace of scholarship and learning in
Japan. Our university mission is to be a top global comprehensive medical university, one that
cultivates “professionals with knowledge and humanity”who embark on a lifetime of service,
advancing the health and social welfare of people in the local community and spreading their
wings to do the same in other communities across the globe.
In recent years, TMDU has undertaken a number of vital initiatives to fulfill its mission. A key
initiative is the Top Global University Project, which the university has launched under the
support of the Ministry of Education, Culture, Sports, Science and Technology (MEXT) to
establish a basis for research and the cultivation of human resources to promote global health care
leaders. Another initiative, critical to dental education and research generally in a super-aging
society such as Japan, is the extension of healthy life expectancy (HALE), which is defined as the
length of life that an individual lives without limitation in daily activities due to health
problems. Furthermore, as a key component of curricular reform in 2011, TMDU established a
center for interprofessional education that brings together medical and dental students to study
holistic medicine / dentistry. In 2014, we also established a new dental education consortium, in
conjunction with 4 other dental schools in Japan (Tohoku University, Niigata university, Tokyo
Dental College, The Nippon Dental University), aimed at developing new platforms for sharing
dental education resources, such as the utilization of an e-learning system.
Through these recent initiatives, the Faculty of Dentistry at TMDU aims to foster dental
practitioners, researchers and educators who can promote and maintain health by providing
comprehensive dental care and contributing to the development of dental medicine and service
from a global perspective.
3
MAY 20th-21st, 2015
TRI-UNIVERSITY CONSORTIUM
O-3
Curriculum Reform for AEC Preparation: Are We on the Right Track?
Suchit Poolthong
Dean of the Faculty of Dentistry, Chulalongkorn University, Bangkok, Thailand
The Association of Southeast Asia Nations (ASEAN) community was formed in 2003 to develop
regional cooperation. This regional alliance has now established an ASEAN Economic
Community (AEC) aiming to make ASEAN a more dynamic and competitive economic
community by creating a single market. Similar to the EU, the AEC focuses on five core elements:
the free flow of goods, services, investment, capital, and skilled labor. Consequently, the free flow
of dental services and professionals will inevitably be established. Therefore, preparation is
necessary for this evolution to proceed smoothly within an appropriate timeframe.
This presentation will propose planning for the free flow of dental services by setting common
dental competencies for ASEAN dentists, followed by curriculum reform of all dental schools in
the member states. Scenarios of these procedures and their effects on neighboring countries
outside the AEC region, such as China and Japan, will also be considered.
4
Research Highlights
MAY 20th-21st, 2015
TRI-UNIVERSITY CONSORTIUM
O-4
The State of the Art of Bone Tissue Engineering-----New Approaches for
Oral Maxillofacial Rehabilitation and Implant Dentistry
Yongsheng Zhou
Peking University School of Stomatology, Beijing, China
Base on the long-term efforts, we have come a long way in bone tissue engineering or bone
regeneration which shows great prospects for oral maxillofacial rehabilitation, and implant
dentistry in the future. However, biological safety, efficiency, feasibility, cost-effectiveness, etc
are still the main factors that preclude its wide usage in clinical translation. In order to
overcome these difficulties, we have developed some new concepts and new approaches in
bone tissue engineering based on human adipose-derived stem cells (hASCs) and cell-homing
strategies. We firstly constructed tissue-engineered bone based on hASCs, human PlateletRich Plasma, and simvastatin which facilitates the future clinical translation because all the
components are easily available. Furthermore, we investigated the potential value of using
primary hASCs, non-osteoinduced hASCs in bone tissue engineering and found that primary
hASCs or non-osteoinduced hASCs could be used directly in the construction of a tissueengineered bone. We also examined if we could use small chemical molecules to enhance
the osteogenic differentiation of hASCs and found that pargyline and CCB1007 could be used to
enhance the osteogenic differentiation of hASCs by which we can use this strategy to improve
the osteogenic capability of stem cells. Next, a cell homing strategy which eliminated
the seed-cell implantation was also introduced in my study. We constructed a novel cell-free
bone tissue engineering system using PLGA loaded with SIM and SDF-1a, and applied it in
critical-sized calvarial defects in mice. At the same time, the underlying mechanisms such as
epigenetic and molecular factors that govern the efficiency, feasibility, and biological safety
of bone tissue engineering or bone regeneration were fully investigated. These preliminary
explorations will facilitate development of new approaches for treatment of oral maxillofacial
defects, oral bone loss (e.g. residual ridge resorption, and bone shortage around implants,
periodontal bone resorption) in the coming era.
Key words: bone regeneration; bone tissue engineering; epigenetics; human adipose-derived stem cells
6
TRI-UNIVERSITY CONSORTIUM
MAY 20th-21st, 2015
O-5
Recent Challenges in Mechanical Stress Analyses for Optimization of Restorative
and Prosthodontic Biomaterials
Noriyuki Wakabayashi
Removable Partial Prosthodontics, Graduate School, Tokyo Medical and
Dental University, Tokyo, Japan
Optimization in restorative methods and designs is hardly implemented without considering the
mechanical aspects of dental biomaterials. This is because the clinical failures of dental restorative
and prosthodontic treatments are often associated with a mechanical stress-induced degradation
in biomaterials, their bonded interface, or the oral tissues. Analyses of mechanical stress in the
materials and the oral tissues are essential to predict potential failures and degradation due to the
masticatory forces and other dynamic loads of associated oral functions. In the last decade, the
mathematical analyses methods that feature a series of computational procedures has been used in
numerous dental research reports. Through the computerized model structures, typically known as
finite element models, the stress and strain are estimated, which are analyzed using visualization
software to evaluate a variety of physical parameters.
The most oral physical phenomena, however, are not adequately simulated by linear static
structures, because they exhibit time-dependent and status-dependent characteristics under stress.
A more realistic simulation requires nonlinearities to reproduce contacts such as between
occluding antagonistic teeth and between the implant and supporting bone. Stress and strain may
change dramatically with the changing status of each contact. The contact simulations have
become an increasingly powerful predictor of the mechanical environment. While, the benefits and
limitations have not been thoroughly examined, particularly for data interpretation. In this
presentation, the key elements required for the design and appropriate utilization of this method
will be discussed, specifically based on recent research on restorative interface, tissue damage
associated with removable prosthodontics, and bone-implant integration. Further advancement
in the mathematical analysis of the human oral structures consisting of the soft and hard tissues
is strongly encouraged to gain a wide range of mechanical solutions that would be beneficial for
dental and oral health science.
Key words: contact; finite element method; implant; mechanical stress; prosthodontics
7
MAY 20th-21st, 2015
TRI-UNIVERSITY CONSORTIUM
O-6
Chitosan as an Antifungal Agent: Mechanisms and Applications
in Dentistry
Oranart Matangkasombut1*, Nicha Ungwijarnpanya2,4, Danaiya Supakanjanakanti2,
Tatcha Chaitrakoonthong2, Prashant Katare3, Worachat Namangkalakul2,
Alitta Promchai2, Rawi Phuprasong2, Teeraphat Pochana2,
Sunpatch Benjavongkulchai2,5, and Panida Thanyasrisung1
Department of Microbiology and DRU on Oral Microbiology
DDS program
3
Graduate program in Oral Biology
4
Department of Orthodontics
5
Department of Radiology
Faculty of Dentistry, Chulalongkorn University, Bangkok, Thailand
1
2
Objective: Candida is a common opportunistic pathogen causing denture stomatitis and oral
candidiasis in immunocompromised patients. As the prevalence of resistance to current antifungal
drugs increases, alternative/adjunctive antifungal agents are in need. We aimed to examine the
activity of chitosan, a natural product with high biocompatibility, against common oral Candida
species and to investigate its antifungal mechanisms using a chemogenomic approach in
Saccharomyces cerevisiae model.
Materials and Methods: Broth dilution assays were performed to determine the minimum fungicidal
concentrations (MFC) of 3 chitosan derivatives against C.albicans, C.glabrata, C.tropicalis,
C.parapsilosis, C.krusei, C.dubliniensis, and S.cerevisiae. Chitosan was applied on acrylic specimens
to test for anti-C.albicans activity. To examine its mode of action, a sublethal concentration of
chitosan was used to screen the haploid deletion library of S.cerevisiae, a collection of yeast strains
with single deletions of virtually all open reading frames in the yeast genome. Genes that when
deleted render yeast cells hypersensitive to chitosan were analyzed using Gene ontology (GO)
analysis tools on Saccharomyces genome database.
Results: A high-molecular weight water-soluble chitosan was active against most Candida species
tested, except C.glabrata. In a gel form at 16xMFC, it was able to completely eliminate C.albicans
on acrylic specimens. From the chemogenomic analysis, genes involved in membranous compartments
were enriched in the list of chitosan hypersensitive yeast mutants, suggesting that chitosan exerts
its fungicidal activity on the yeast cell membrane.
Conclusion: Chitosan is active against most common oral Candida species and could inhibit
C.albicans when applied on acrylic specimens. The target of chitosan activity is likely the fungal
cell membrane. Due to its many advantageous properties, chitosan is a promising antifungal agent
for oral applications.
Key words: Antifungal agent; Candida; chitosan
8
Clinical Research
MAY 20th-21st, 2015
TRI-UNIVERSITY CONSORTIUM
O-7
Application of Synchrotron Radiation X-ray for the Clinical Diagnosis
Motohiro Uo
Tokyo Medical and Dental University, Tokyo, Japan
The oral and the respiratory mucosae are exposed to various dental restorative materials and
inhaled airborne debris and induce various symptoms. Therefore, the analysis of eroded
metallic ions and foreign objects in tissues is important for the definite diagnosis. However, the
histopathological specimens are specific to each case and patient, thus, the elemental analysis
should be carried out non-destructively. Synchrotron radiation X-ray fluorescence (SR-XRF)
analysis is the suitable method for the trace element analysis in the histopathological specimens.
We applied SR-XRF for the detection of the eroded metallic elements from the dental restoratives
and implants into oral mucosa. Also, the inhaled foreign objects, which induced characteristic lung
disease, could be identified by SR-XRF. Those analyses could be carried with the thin sectioned
paraffin embedded specimens which are popularly used for the histopathological analysis. Therefore,
it would be versatile method for various tissue analysis.
Key words: elemental analysis; synchrotron radiation; trace element; x-ray fluorescence
10
TRI-UNIVERSITY CONSORTIUM
MAY 20th-21st, 2015
O-8
Comparative Histological Study in Maxillary Sinus Augmentation
Using Coarse or Fine Particle of Xenograft Materials
(Preliminary Report)
Paksinee Kamolratanakul
Department of Oral Surgery, Faculty of Dentistry, Chulalongkorn University,
Bangkok, Thailand
Objective: To compare the histology of the bone healing in maxillary sinus augmentation using
coarse grained particle or fine grained particle of xenograft materials.
Materials and Methods: Double blinded, clinical trial study was performed in 10 patients with
posterior maxillary edentulous ridge associated with sinus pneumatization. Patients were
subjected to lateral window technique of sinus lift procedure using xenograft material
commercially prepared as coarse particle grafting (1-2mm) in first group and fine particle
(0.25-1mm) in second group. Bone specimens were harvested after 6 months of augmentation and
subjected to histomorphological analysis for newly-formed bone, residual particle and fibrous
tissue formation.
Results: The preliminary data initially showed more newly-formed bone significantly
(p value=0.002) in the group of sinus lift using coarse particle of xenograft (mean
of percentage area=22.47%,) compared to the group using fine particle of xenograft (mean of
percentage area=11.26%). Residual particle in the group of coarse particle xenograft (mean of
percentage area=6.19%) was more than in the group of fine particle xenograft (mean of
percentage area=1.88%) without the statistic significance. The group of fine particle xenograft revealed
abandon of fibrous tissue surrounding the space of particle (mean of percentage area=86.85%)
significantly compared to the group of coarse particle xenograft (mean of percentage area=71.38%)
with p value=0.021.
Conclusion: Coarse particle of xenograft material trends to promote more newly-formed bone in
maxillary sinus augmentation which is possibly due to the more space between particle that
provides enough space for ingrowth bone cell, cell adhesion and migration of neovascularization.
We further study the immunohistochemistry to evaluate the bone healing and microstructure of
newly-formed bone will be analyzed using micro-computerized tomography.
Key words: maxillary sinus augmentation; xenograft
11
MAY 20th-21st, 2015
TRI-UNIVERSITY CONSORTIUM
O-9
Basic Study Focused on Fitting Accuracy of Thermoplastic
Resin for Non-Metal Clasp Denture
Junichiro Wada*, Kenji Fueki, Masaru Yatabe, Hidekazu Takahashi and
Noriyuki Wakabayashi
Tokyo Medical and Dental University, Tokyo, Japan
Objective: To incorporate a metal framework into non-metal clasp dentures (NMCDs), the
dimensional accuracy of thermoplastic resins requires precision equivalent to conventional acrylic
resins. This study aimed to evaluate the ftting accuracy of thermoplastic resins compared to
heat-cured acrylic resin.
Materials and Methods: Five thermoplastic resins (polyethylene terephthalate [EstheShot, ES;
EstheShot Bright, ES-B], polyamide [Lucitone FRS, LF], polycarbonate [Reigning Resin N, RN]
and a heat-curing acrylic resin [Acron, AC]) were used. The specimens were created on master
casts constructed of high- strength stone that simulated a maxillary edentulous ridge. Additionally,
high-expansion stone was used as the master cast for RN specimens as recommended by the
manufacturer. The ES-B, LF and RN specimens were prepared with and without annealing after
injection molding. The gaps between the molded resin and the cast were measured.
Results: ES had the smallest gap and was significantly smaller than AC (p<0.05). The gap sizes of
ES-B, LF and RN (high-expansion stone) without annealing were similar to AC (p>0.05), while
the gap size of RN (high-strength stone) with and without annealing was significantly greater than
AC (p<0.001). The gap sizes of ES-B and LF with annealing were significantly less than AC
(p<0.05). Further, the gap sizes of ES-B, LF and RN with annealing were significantly smaller than
the gaps without annealing (p<0.05).
Conclusion: The results suggested that ES, ES-B and LF have adequate fitting accuracy for
incorporating metal framework into NMCDs and that annealing effectively improved the fitting
accuracy of ES-B, LF and RN.
Key words: denture base; fitting accuracy; non-metal clasp denture; removable partial denture;
thermoplastic resin
12
Basic Science Research I
MAY 20th-21st, 2015
TRI-UNIVERSITY CONSORTIUM
O-10
Effects of Compatibility of Deproteinized Antler Cancellous Bone with
Various Bioactive Factors on Their Osteogenic Potential
Yan Wei
Department of Geriatric Dentistry, School and Hospital of Stomatology,
Peking University, Beijing, China
Objective: To investigate the compatibility of calcinated antler cancellous bone (CACB) scaffolds
with various bioactive factors including icariin (ICA), velvet antler polypeptides (VAP) or recombinant
human bone morphogenetic protein-2 (rhBMP-2) as well as their combinational osteogenic potential
in vitro and in vivo.
Materials and Methods: The cancellous parts of naturally shed Sika deer antlers were calcinated
and characterized. The distribution, chemical stability and in vitro release profiles of the reagents
on CABC were illustrated. In vitro bioactivity on rat bone marrow mesenchymal stem cells were
assayed in aspects of cell attachment, proliferation, alkaline phosphatase activity, osteogenic gene
expression, and mineralization. In vivo osteogenesis in rabbit mandible critical-sized defects were
evaluated with microcomputed tomography (µ-CT) scanning evaluation, histological analysis,
immunohistochemical analysis and real-time quantitative RT-PCR analysis.
Results: The calcinated antler, with porous and interconnected network structure, consisted
primarily of hydroxyapatite doped with traces of fluoride, chloride and carbonate ions. Uniform
distribution and chemical stability of the reagents on CABC were confirmed. A relatively stable
release of ICA, a burst release of VAP, and only minimal release of rhBMP-2 from the corresponding
composites were observed over a 14-day period in vitro. ICA/CACB composites displayed the
most marked positive effects on rBMSC attachment, proliferation, osteogenic differentiation and
mineralization. The quanlity and quantity of in vivo bone formation and neovascularization with
the ICA/CACB implant were superior compared to those of the VAP/CACB and rhBMP-2/CACB
composites. Low pro-inflammatory (TNF- α, IL-6) and high anti-inflammatory (IL-10) mRNA
levels were observed at scaffold implantation sites which were in close association with amount
of new bone formation.
Conclusion: These findings highlight that the compatibility between scaffolds and bioactive
factors should been taken into account when considering the formula of optimized bone defect
repair.
Key words: antler; compatibility; icariin; osteogenic potential; rhBMP-2; VAP
14
TRI-UNIVERSITY CONSORTIUM
MAY 20th-21st, 2015
O-11
Targeted Deletion of Cathepsin K in the Osteoclast Lineage
Couples Bone Resorption to Formation through S1P-dependent
Mechanism
Sutada Lotinun1*, R. Kiviranta1,2, J. Vacher3, E. Vuorio2, W. C. Horne1, R. Baron1
Department of Oral Medicine, Infection and Immunity, Harvard School of
Dental Medicine, Boston, MA, USA and Department of Physiology,
Chulalongkorn University, Bangkok, Thailand
2
Department of Medical Biochemistry, University of Turku, Finland
3
Department of Cellular Interactions and Development, Faculté de Médecine de l’Université de
Montréal, Québec H2W 1R7, Canada
1
Genetic deficiency of cathepsin K (Ctsk) in humans causes pycnodysostosis. It has been reported
that Ctsk-null mice have high bone formation rate (BFR) and high numbers of poorly functional
osteoclasts (OCs). However, Ctsk was globally deleted, it could not be determined whether the
increased BFR resulted from effects in osteoblasts (OBs) or secondary to changes in OC-generated
coupling factors. We generated conditional Ctsk knockouts (Ctskfl/fl mice). Deletion of Ctsk in
hematopoietic cells using Mx1-cre resulted in moderate osteopetrosis with increases in cancellous
bone volume (+163%) and OC number (+178%) compared to controls. Interestingly, BFR and
OB number were also markedly increased (+188% and +214%, respectively). In vitro assays of
primary OBs derived from the long bones showed that both alkaline phosphatase and mineralized
bone nodules were increased in cells derived from Mx1-Cre;Ctskfl/fl mice, compared to controls.
In contrast, deletion of Ctsk in OBs using Osx-Cre had no effect on bone resorption or BFR. To
determine whether the increased BFR was OC-dependent, we targeted deletion of Ctsk
specifically to the OC lineage by crossing with CD11b-cre mice. CD11b-Cre-induced Ctsk
deficiency increased OC number but also resulted in increases in several indices of bone formation
(MS, MAR, BFR, and OB number), demonstrating that the increased BFR is OC-mediated. These
changes were associated with increases in steady-state mRNA levels for OB marker genes, osterix
and osteocalcin. To examine if OC-derived coupling factors were altered in these mice, we
examined gene expression of coupling factors, including sphingosine kinase, an enzyme
that catalyzes the phosphorylation of sphingosine to sphingosine 1-phosphate (S1P), wnt10b and
ephrin b2 in vitro. Deletion of Ctsk in OCs increased their sphingosine-kinase 1 expression.
Mx1;Ctskfl/fl OC-conditioned medium, which contained elevated levels of S1P, increased
alkaline phosphatase and mineralized nodules in OB cultures and an S1P1,3 antagonist inhibited
the responses. Mx1;Ctskfl/fl OBs expressed an increased RANKL/OPG ratio, providing a positive
feedback loop to increase OC number. Our results provide genetic evidence that Ctsk modulates
the coupling between bone resorption and formation in vivo by antagonizing the generation of the
OC-derived coupling factor S1P.
Key words: cathepsin K, osteoporosis, osteoclast, sphingosine 1-phosphate
15
MAY 20th-21st, 2015
TRI-UNIVERSITY CONSORTIUM
O-12
Immunohistochemical and Gene-expression Analysis of Pulp Injury-induced
Glial Cell Activation in the Rat Thalamus
Jun Kawamura1*, Tomoatsu Kaneko2, Yusuke Yamanaka2, Takafumi Ito2,
Mitsuhiro Sunakawa1, Takashi Okiji1
Pulp Biology and Endodontics, Department of Oral Health Sciences,
Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental
University, Tokyo, Japan
2
Division of Cariology, Operative Dentistry and Endodontics, Niigata University Graduate
School of Medical and Dental Sciences, Niigata, Japan
1
Objective: We have recently reported that mechanical pulp exposure induces increased
neuronal activity and glial cell activation in the thalamus in rats. To provide further insight
into the mechanism of the pulp injury-induced glial-neuronal interaction, we here examined the
effect of local anesthetic pretreatment of the pulp-exposed teeth on the thalamic expression of
p38-mitogen-activated protein kinase (MAPK; known to participate in the microglial nociceptive
processing), glial fibrillary acidic protein (GFAP; an astrocytic activation-associated molecule),
and CD86 (an antigen presenting cell-related molecule).
Materials and Methods: A local anesthetic (2% lidocaine with 1/80,000 epinephrine; AstraZeneca)
or saline was injected into the tissue surrounding the mandibular left first molar of Wistar rats. The
tooth was then pulp-exposed, and the cavity was sealed with flowable resin composite (UniFill
Flow, GC). After 0 h (normal pulp) and 72 h, the contralateral thalamus was retrieved and
subjected to immunohistochemistry for GFAP, and real-time PCR analysis for p38-MAPK
families (MAPK 13 and MAPK 14), GFAP, and CD86 mRNAs.
Results: Significant increase of GFAP(+) astrocytes was observed only in the saline-pretreated
groups at 72h. Expression levels of MAPK 13 and 14, GFAP, and CD86 mRNAs in the local
anesthetic-pretreated groups were significantly lower than those in the saline-pretreated groups at
72h.
Conclusion: Local anesthetic pretreatment attenuated the pulp injury-induced up-regulation of
GFAP, CD86 and MAPK 13 and 14 mRNAs and increase of GFAP-expressing astrocytes in the
contralateral thalamus.
Key words: dental pulp; glial cell; p38-MAPK; thalamus
16
Basic Science Research II
MAY 20th-21st, 2015
TRI-UNIVERSITY CONSORTIUM
O-13
In Vitro Cytotoxicity of Mussel-Mimetic Bio-adhesive Polymers
in Comparison with Conventional Dental Materials
Noriko Hiraishi*, Masayuki Otsuki, Daisaku Kaneko, Junji Tagami
Tokyo Medical and Dental University, Tokyo, Japan
Objectives: Mussel-mimetic bio-adhesive polymers are synthesized by the transesterification of
two plant-derived sources, 3,4-dihydroxyhydrocinnamic acid (DHHCA) and 3-(3-hydroxyphenyl)
propionic acid (3HPPA). The strong adhesive action of poly (DHHCA-co-3HPPA) is caused by
interactions between catechol groups at the end of the polymer terminal chains and the
substrate surface. In this study, the in vitro biocompatibility and physicochemical properties of
poly (DHHCA-co-3HPPA) were compared with those of conventional dental adhesive materials,
glass ionomer cement (GCI) and adhesive resin (AR).
Materials and Methods: Substances released in water at 37ºC from tested materials were analyzed
by mass spectrometry. The biocompatibility of poly (DHHCA-co-3HPPA) was evaluated in vitro
by MTT assay and alkaline phosphatase (ALP) activity testing using pulpal cells, and compared
with that of GIC and AR.
Results: Poly (DHHCA-co-3HPPA) released a limited amount of eluates in the form of dimers,
trimers and oligomers of (DHHCA-co-3HPPA), and did not release unreacted residues, while
released substances were detected for GIC and AR. For both MTT and ALP assays, two-way
ANOVA revealed that “exposure time (48 h and 72 h)” and “materials” were both significant factors (both p<0.001) and interaction between the two factors was also significant (p<0.001). MTT
assay and ALP activity revealed the relative cell viability of the poly (DHHCA-co-3HPPA) group
when compared with GIC and AR.
Conclusion: The eluted substances of glass ionomer and adhesive resin accounted for their low
biocompatibility. Since poly (DHHCA-co-3HPPA) has an aromatic hyperbranched architecture
with abundant catechol end groups, this mussel-mimetic adhesive exhibited degradation resistance
and good biocompatibility.
This study was financially supported by a New Energy and Industrial Technology Development
Organization (NEDO, Project ID: 11B16002d).
Key words: alkaline phosphatase activity; biocompatibility; mass spectrometry; MTT assay;
Mussel-mimetic bio-adhesive; polymer
18
TRI-UNIVERSITY CONSORTIUM
MAY 20th-21st, 2015
O-14
The Development of Prostacyclin Drug Delivery System for
Bone and Tooth Regeneration
Chalida Nakalekha Limjeerajarus*
Faculty of Dentistry, Chulalongkorn University, Bangkok, Thailand
Regenerative endodontics is an emerging field in tissue engineering that involves the use of stem
cells, scaffolds, and inductive molecules to revascularize and regenerate the pulp/dentin complex.
The dental pulp is a highly vascularized connective tissue surrounded by mineralized tooth
structure and plays important role for maintaining tooth vitality since it provides nutrition and acts
as biosensor to detect pathogenic stimuli. Thus, maintaining pulp vitality is extremely important
in operative and endodontic treatment. Potentiality of successful pulp and tooth regeneration and
revascularization therapies is increasing due to accumulated knowledge of stem cells, growth
factor and promoting molecules. The low-compliance organ, as well as dental pulp tissue, could
cause the decrease of vasculature and subsequently inhibit the proliferation of the stem cells. The
use of bioactive molecules could accelerate and/or induce the formation of a tertiary dentin bridge.
Prostacyclin (PGI2), a strong physiologic vasodilating agent, has a biogenic property by enhancing
angiogenesis and cellular proliferation. Iloprost; a stable synthetic PGI2 analog, can promote
neovascularization and bone formation. We found that iloprost could enhance the revascularization
and reparative dentin formation in vitro and in vivo. We aimed to develop a drug delivery system
to deliver analog of prostacyclin to be used in tooth regeneration. Our long term aim is fully
reconstructing of a functional dental tissue by tissue engineering using PGI2 together with other
inorganic materials could be a promising modality that can increase success rate in dental
treatment.
Key words: drug delivery; prostacyclin; tooth regeneration
19
MAY 20th-21st, 2015
TRI-UNIVERSITY CONSORTIUM
O-15
The Effects and Epigenetic Mechanisms of TiO2 Nanotubes
on the Osteogenic Differentiation of Human Adipose-derived
Stem Cells
Longwei Lv*, Yongsheng Zhou
Peking University School of Stomatology, Beijing, China
Objective: To investigate the effects of TiO2 nanotubes on the osteogenic differentiation of
human adipose-derived mesenchymal stem cells (hASCs) in vitro and in vivo, and to select the
optimal dimension of TiO2 nanotubes. To explore the possible epigenetic mechanism regulating
enhanced osteogenic differentiation of hASCs by TiO2 nanotubes.
Materials and Methods: Different diameters of TiO2 nanotubes were prepared by anodic oxidation.
Meanwhile, sandblasting with large grit and acid-etching (SLA) surface was chosen as
a application. Furthermore, biochemical, molecular, and epigenetic approaches were utilized to
screen how nanotopography directs stem cell fate.
Results: Both in vitro and in vivo studies demonstrated that the nanoscale geometry influenced
cellular differentiation and TiO2 nanotubes with a diameter of 70 nm was the optimal dimension
for the osteogenic differentiation of hASCs. Moreover, we observed that TiO2 nanotubes
promoted the osteogenic differentiation of hASCs by upregulating methylation level of histone
H3 at lysine 4 (H3K4) in the promoter regions of osteogenic genes Runx2 and osteocalcin, by
inhibiting demethylase retinoblastoma binding protein 2 (RBP2). These results revealed, for the
first time, the epigenetic mechanism by which nanotopography directs stem cell fate.
Conclusion: Nanoscale geometry can influence cell differentiation, and 70 nm TiO2 nanotubes
are optimal for the osteogenic differentiation of hASCs, as compared with 50 nm and 100 nm, and
are better than SLA both in vitro and in vivo. Nanoscale geometry can regulate the osteogenic
differentiation of hASCs via an epigenetic mechanism: the appropriate nanotopography can
upregulate the methylation level of H3K4 at the promoter regions of osteogenesis associated genes
by inhibiting of RBP2 expression.
Key words: adipose-derived stem cells; bone tissue engineering; epigenetics; nanotubes, osteogenic
differentiation; titanium
20
TRI-UNIVERSITY CONSORTIUM
MAY 20th-21st, 2015
O-16
Lithium Disilicate Glass-ceramic Liner Increases the
Shear Bond Strength between Feldspathic Porcelain and
Zirconium Oxide
Kamolporn Wattanasirmkit*, Viritpon Srimaneepong, Kanchana Kanchanatawewat,
Naruporn Monmaturapoj, Pasutha Thunyakitpisal , Supatra Jinawath
Faculty of Dentistry, Chulalongkorn University, Bangkok, Thailand
Objective: To investigate the shear bond strength (SBS) between veneering porcelain and zirconia
substructure using lithium disilicate glass-ceramic as a liner.
Materials and Methods: The composition and morphology of the commercial glass-ceramic liner
and the lithium disilicate glass-ceramic were analyzed by XRD and SEM, respectively. The
optimum firing time and temperature of lithium disilicate glass-ceramic used as a liner between
veneering porcelain and zirconia substructure were investigated. After baking the glass-ceramic
liner or commercial glass-ceramic liner and veneering porcelain over zirconia substructures, the
specimens were stored in distilled water and tested using a universal testing machine. SBS was
determined for the lithium disilicate glass-ceramic groups and compared to the
commercial glass-ceramic liner group. The lithium disilicate glass-ceramic group with the
highest bond strength was subjected to thermocycling at 5,000 and 10,000 cycles and compared
to the commercial glass–ceramic liner. SBS values were analyzed using ANOVA. Fractographic
analyses were observed under a stereomicroscope and back scattered mode SEM.
Results: The SBS between veneering porcelain and zirconia substructure was significantly
improved (p<0.05) when lithium disilicate glass-ceramic liner was fired at 850°C. The SBS of all
groups after thermocycling were higher than the acceptable critical limit of 25 MPa.
Conclusion: Using lithium disilicate glass-ceramic could create higher bond strength between
zirconia substructure and veneering porcelain than commercial glass-ceramic liner. However, time
and duration of firing lithium disilicate glass-ceramic had an influence on its microstructure.
Key words: glass-ceramic; lithium disilicate; shear bond strength; zirconia
21
MAY 20th-21st, 2015
TRI-UNIVERSITY CONSORTIUM
O-17
Establishment of Occlusion in a Virtual Environment:
Workflow and Accuracy
Xiao-jing Liu*, Qian-qian Li, Tong-tong Li3, Zheng Xie, Yi Zhang
Peking University School of Stomatology, Beijing, China
Objective: Although computer-assisted surgical simulation is becoming increasingly popular, few
studies have reported it use for establishing occlusion. This study aimed to investigate the feasibility
of a modified workflow of virtual occlusion establishment.
Materials and Methods: A daemon software was developed based on visualization, collision
detection, and mesh editing algorithms and the principle of visual analysis. A virtual workflow was
then established to set the relationship between the upper and lower dentitions in a virtual
environment. The reproducibility and accuracy of the workflow were investigated using a 60-model
test. Errors between virtually set position (test) and manually set position (gold standard) were
calculated by 37 pairs of point-to-point measurements. Inter- and intra-user correlation tests, the
Student–Newman–Keuls test, and one-way ANOVA were used to investigate the reproducibility of
key procedures in the workflow. The time expense of both procedures was recorded.
Results: The point-to-point errors of each tooth were all not significantly larger than 1 mm (p>0.05).
All inter- and intra-user correlation coefficients were >0.95, while errors did not differ between
different teeth and models (F=0.873, p>0.05). The time expense for the test and control procedures
were 13.4±11.2 min and 32.7±28.4 min, respectively.
Conclusion: In conclusion, the workflow for establishing virtual occlusion was found to be less
time consuming, and more reproducible and accurate. It is suitable for clinical applications.
Key words: collision detection; computer-assisted surgical simulation; virtual occlusion; visual
analytics
22
TRI-UNIVERSITY CONSORTIUM
MAY 20th-21st, 2015
O-18
MiR-29b Suppresses Proliferation, Migration, and Invasion
of Tongue Squamous Cell Carcinoma through PTEN-AKT
Signaling Pathway by Targeting Sp1
Ling-fei Jia*, Ye-hua Gan, Guang-yan Yu
Peking University School and Hospital of Stomatology, Beijing, China
Objective: miR-29b has been implicated in various cancers. However, the role of miR-29b in
tongue squamous cell carcinoma (TSCC) remains unclear. This study aimed to investigate the role
of miR-29b in TSCC progression.
Materials and Methods: The expression of miR-29b was analyzed in TSCC tissues and cells.
Functional studies were performed in TSCC cells. Real time-PCR, Western blot, cell proliferation,
transwell, and dual luciferase reporter assays were performed according to standard procedures.
Results: miR-29b was significantly decreased in TSCC specimens and cell lines compared with
corresponding normal counterparts. Overexpression of miR-29b significantly inhibited the
proliferation, migration, invasion, and cell-cycle progression of TSCC cells, and promoted
apoptosis. Moreover, miR-29b targeted the 3´ untranslated region of the Sp1 transcript and
resulted in the deregulation of Sp1. The inhibition of Sp1 by miR-29b subsequently resulted in the
upregulation of PTEN, leading to a decline of phosphorylated AKT. Knockdown of Sp1 in TSCC
cell lines mimicked the effects of miR-29b overexpression. In addition, the expression of miR-29b
was inversely correlated with Sp1 and positively correlated with the PTEN in TSCC specimens.
Conclusion: miR-29b functions as a tumor suppressor in TSCC, and the miR-29b/Sp1/PTEN/
AKT axis might represent a potential therapeutic target for TSCC intervention.
Key words: AKT; miR-29b; oral cancer; PTEN; Sp1; tongue squamous cell carcinoma
23
Research by PhD students
TRI-UNIVERSITY CONSORTIUM
MAY 20th-21st, 2015
O-19
Integrated Profiling of mRNAs and microRNAs to Identify
Potential Biomarkers for Oral Malignant Transformation
Wen Shi1,2*, H. Hua3, D. Zhou2, Z. Cai1
Department of Oral and Maxillofacial Surgery, Peking University School
and Hospital of Stomatology, Beijing, China
2
State Key Laboratory of Natural and Biomimetic Drugs, Peking University,
Beijing, China
3
Department of Oral Medicine and Traditional Chinese Medicine, Peking University, School and
Hospital of Stomatology, Beijing, China
1
Background: So far the next generation sequencing (NGS) had been applied in many
disease-related fields, providing better understanding of molecular pathways leading to cancer,
which allowed a better way exploring biomarkers with reasonable sensitivity and specificity for
oral squamous carcinoma (OSCC) and its malignant transformation.
Objectives: The purpose of this study was to systematically profile the expression of both mRNAs
and miRNAs in OSCC and its premalignant disease to identify some novel potential biomarkers
for the detection of malignant transformation.
Materials and Methods: NGS was applied to investigate the differential transcriptome. The
expression of mRNAs and miRNAs were analyzed in tumor tissues, premalignant tissues and
adjacent normal tissues obtained from same OSCC patients with long history of oral mucosal
disease. Some of the most interesting genes and miRNAs were screened from NGS data. Then,
quantitative real-time PCR (qPCR) was used for validation of them in a large cohort of patients
and volunteers from healthy population.
Results and Conclusions: As part of the NGS results, hundreds of miRNAs and thousands of
genes were detected to be differentially expressed. We also identified several novel miRNA
candidates. Comparison among qPCR validation results revealed significantly different expression of
certain genes and miRNAs in different morbid states. Our study provided a map of the mRNA and
miRNA expression profiles of OSCC and the malignant transformation using deep sequencing
technology. However, for early detection of malignant transformation the feasibility of these
targets needs to be analyzed in the future study.
Key words: miRNA; next generation sequencing; oral squamous cell carcinoma; premalignant
disease
25
MAY 20th-21st, 2015
TRI-UNIVERSITY CONSORTIUM
O-20
Tooth Regenerative Therapy by Utilizing a Split Tooth Germ
Naomi Yamamoto1*, Masamitsu Oshima2, Chie Tanaka3, Keiji Moriyama1 and
Takashi Tsuji3, 4, 5
Maxillofacial Orthognathics, Tokyo Medical and Dental University,
Tokyo, Japan
2
Oral Implantology & Regenerative Dental Medicine Graduate School, Okayama University,
Okayama, Japan
3
Biological Science and Technology, Graduate School of Industrial Science and Technology,
Tokyo University of Science, Chiba, Japan
4
Organ Technologies Inc., Tokyo, Japan
5
RIKEN Center for Developmental Biology, Kobe, Japan
1
Objective: Conventional methods of replacing lost teeth include fixed or removable prosthodontics,
dental implants and tooth auto-transplantation. A promising alternative is auto-transplantation of
tooth germ, a biological treatment that may benefit patients in need of intact replacement teeth with
healthy periodontal tissues. Because there is a limit to the number of tooth germs available in each
individual, we aimed to develop a new method for multiplying the number of teeth generated from
a single tooth germ during its developmental process.
Materials and Methods: To confirm the ability of a tooth germ to develop into two normal teeth,
the molar tooth germs in the cap stage were extracted from the jaw bones of mice, split in vitro by
ligation with a thread, and transplanted into a mouse subrenal capsule in vivo. We observed the
distinct gene expression profile and cell dynamics characteristics of the normal tooth developmental
process. We investigated whether a split tooth germ could be engrafted after being transplanted
into an edentulous area, and these teeth can also restore physiological tooth functions such as the
response to mechanical stress and the perceptive potential for noxious stimulations.
Results: The ligated tooth germs developed successfully into two healthy teeth with normal
periodontal structures including cementum, periodontal ligament and alveolar bone. When
transplanted into an edentulous area, these teeth erupted fully into contact with the opposing tooth
through normal physiological periodontal tissue remodeling. Furthermore, these teeth responded
normally to noxious stimuli via nerves in vivo, suggesting that these teeth establish and maintain
communication with the central nervous system. Finally, these teeth moved in response to the
application of orthodontic forces.
Conclusion: These findings indicate that a single tooth germ can be multiplied. This technique
may form the basis of a new biological paradigm for tooth regeneration that uses feasible graft
materials such as third molar tooth germs.
Key words: regenerative therapy; split tooth germ; tooth development; transplantation
26
TRI-UNIVERSITY CONSORTIUM
MAY 20th-21st, 2015
O-21
Rinsing with Saline Promotes Gingival Fibroblast Wound
Healing in Vitro
Nam Cong-Nhat Huynh1,2*, Prasit Pavasant1,3, Ruchanee Salingcarnboriboon
Ampornaramveth2
Mineralized Tissue Research Unit, Faculty of Dentistry, Chulalongkorn
University, Bangkok, Thailand
2
DRU in Oral Microbiology, Microbiology Department, Faculty of Dentistry, Chulalongkorn
University, Bangkok, Thailand
3
Department of Anatomy, Faculty of Dentistry, Chulalongkorn University, Bangkok, Thailand
1
Objective: Rinsing the mouth with sodium chloride solution is believed to lead to healthy gums
and hasten oral ulcer healing. Although there is no scientific evidence to support this belief, many
dentists advise their patients to do so. The purpose of this study was to investigate the in vitro
effect of short-term rinsing with sodium chloride (NaCl) on gingival fibroblast wound healing and
clarify the underlining mechanisms.
Materials and Methods: Primary human gingival fibroblasts (hGFs) were isolated from the
gingiva attached to teeth extracted from healthy volunteers. Confluent hGF cultures received
scratch-test assays that were rinsed with concentrations of NaCl ranging from 0–7.2% for 2 min,
3 times a day. Proliferation and cell migration in cultures treated as described above were assessed
by MTT and transwell migration assay, respectively. The expression of the extracellular matrix
proteins Collagen 1 (COL1) and Fibronectin (Fn) were assessed by semi-quantitative RT-PCR.
Changes in the cytoskeleton proteins Focal Adhesion Kinase (FAK) and F-actin were detected by
immunofluorescence.
Results: Rinsing with 0.9 and 1.8% NaCl significantly promoted hGF wound healing and the
highest dose of NaCl (7.2%) inhibited healing, respectively, compared to control. NaCl rinsing
did not affect hGF proliferation; however, it did significantly increase cell migration and adhesion
area. Rinsing with 1.8% NaCl significantly up-regulated the expression of COL1 >3 fold. A slight,
but significant, change in Fn expression was also observed. Up-regulation of FAK and F-actin,
molecules responsible for cytoskeleton re-organization and cell migration, were detected after
rinsing with 1.8% NaCl solution.
Conclusion: NaCl solution promotes hGF wound healing in vitro by increasing cell migration,
alteration of cytoskeleton molecules (FAK and F-actin), and enhancing extracellular matrix
production (COL1 and Fn). These data represent the first scientific evidence supporting the long
held belief in the benefits of using NaCl mouth rinse.
Key words: cell migration; focal adhesion kinase; gingival fibroblast; sodium chloride; wound
healing
27
Poster Presentation
Group 1 P1-P10
TRI-UNIVERSITY CONSORTIUM
MAY 20th-21st, 2015
P-1
Thrombospondin-1 Expression by Periodontal Pathogen via Toll-like Receptor 2
Misa Gokyu*, Hiroaki Kobayashi, Hiromi Nanbara, Takeaki Sudo, Yuichi Ikeda,
Tomonari Suda, Yuichi Izumi
Tokyo Medical and Dental University, Tokyo, Japan
Objective: Periodontitis is a chronic inflammatory disease caused by gram-negative anaerobic
bacteria. Monocytes and macrophages stimulated by periodontopathic bacteria induce inflammatory
mediators that cause tooth-supporting structure destruction and alveolar bone resorption. In this
study, using a DNA microarray, we identified the enhanced gene expression of thrombospondin-1
(TSP-1) in human monocytic cells stimulated by Porphyromonas gingivalis LPS. TSP-1 is a
multifunctional extracellular matrix protein that is upregulated during the inflammatory process
and mediate immune responses. Recent studies reported that TSP-1 is associated with rheumatoid
arthritis and osteoclastogenesis. However, TSP-1 expression in periodontitis and the mechanisms
underlying TSP-1 expression in human monocytic cells remain unknown. The purpose of this
study was to evaluate TSP-1 expression in periodontal gingival tissues and to investigate the
modulation of TSP-1 expression by periodontopathic bacteria.
Materials and Methods: We used a human acute monocytic leukemia cell line (THP-1). P.
gingivalis LPS, Pam2CSK4, E. coli LPS, IL-4, IL-17A, IL-17F and IFN-γ were used for
stimulation. TLR2-neutralizing antibody and TLR4-neutralizing antibody were used to block the
biological activity of TLRs. MG-132 was used for a specific inhibitor of NF-kB. Human gingival
tissues were obtained during periodontal surgery. TSP-1 expression was analyzed by real time
RT-PCR for mRNA expression and ELISA for protein production.
Results: TSP-1 mRNA expression level was significantly upregulated in periodontitis gingival
tissues and in P. gingivalis LPS-stimulated THP-1 cells. TSP-1 was expressed via TLR2 and TLR4
pathways. In P. gingivalis LPS stimulation, TSP-1 expression was dependent upon TLR2 through
the activation of NF-kB signaling. Furthermore, IL-17F synergistically enhanced P. gingivalis
LPS-induced TSP-1 production.
Conclusion: These results suggest that modulation of TSP-1 expression by P. gingivalis plays an
important role in the progression and chronicity of periodontitis. It may also contribute a new
target molecule for periodontal therapy.
Key words: periodontitis, P. gingivalis, Thrombospondin-1
29
MAY 20th-21st, 2015
TRI-UNIVERSITY CONSORTIUM
P-2
Hierarchical Intrafibrillarly-mineralized Collagen Scaffolds for
Mandible Regeneration
Shuai Liu*, Yan Liu, Yanheng Zhou
Peking University School of Stomatology, Beijing, China
Objective: Bone tissue engineering is based upon scaffold biomaterials that support ingrowth of
tissue. Traditional scaffolds only mimic the chemical component of extracellular matrix (ECM) of
natural bone. Scaffolds with similar hierarchical nanostructure to ECM haven’t been developed.
We aim to fabricate intrafibrillarly-mineralized collagen scaffold (IMC), which can mimic natural
bone hierarchical structure from multiple levels, compare its regeneration ability with pure collagen
(Col) and b-TCP scaffolds, investigate the nanostructure of new bone and further mechanism.
Materials and Methods: Using modified biomimetic approach to fabricate IMC scaffold.
Morphology and ultra-structure of IMC scaffolds was determined by SEM and TEM. Scaffolds
loaded with BMSCs was implanted in rat defects. Micro-CT, histological staining, SEM and TEM
were used to evaluate the quantity and quality of new bone. Interaction between BMSCs and
scaffolds was investigated in vitro. EDS was used to detect the secretion and mineralization
behavior of BMSCs.
Results: The IMC scaffold exhibited excellent osteoinductivity, osteoconductivity and proper
degradability, increased bone regeneration in vivo. New bone in IMC group exhibited ordered
nano-structure the most similar to natural bone. In vitro study showed that hierarchical IMC
scaffold improved both secretion and mineralization of BMSCs, mineralized ECM was detected
on cell surface. ECM was seen in Col group without any indication of mineralization. In b-TCP
group, only calcified nodules was seen without obvious organic matrix.
Conclusion: Hierarchical IMC scaffold with biomimetic ultra-structure improved bone formation
in vivo and ECM secretion, mineralization in vitro. These findings indicated that chemical composition and
nanostructure of supporting scaffolds determined the destiny of ECM which makes IMC promising
candidate for bone tissue engineering.
Key words: bone regeneration; extracellular matrix; hierarchical; intrafibrillarly-mineralization; nanostructure
30
TRI-UNIVERSITY CONSORTIUM
MAY 20th-21st, 2015
P-3
Effect of Aloe Vera on Oral Pathogens in Healthy Volunteers
Titipong Prueksrisakul, Soranun Chantarangsu*, Pasutha Thunyakitpisal
Faculty of Dentistry, Chulalongkorn University, Bangkok, Thailand
Objective: To investigate the anti-bacterial effect of Aloe vera juice against Lactobacillus spp. and
Streptococcus mutans in Thai healthy volunteers.
Materials and Methods: Fifty-three healthy volunteers (34 females and 19 males) participated.
Prior to the experiment, subjects were interviewed for past history of allergy, current systemic
diseases and medications. Subjects daily received 250 ml of fresh Aloe vera juice for 14 consecutive
days. At day 0 and day 15 of the experiment, saliva collection and interpretation for the number
of Lactobacillus bacteria and Streptococcus mutans were performed. The scores level of bacterial
concentration at baseline and 14 days post-intervention were compared by the Wilcoxon matched
paired signed ranks test.
Results: Significant reduction in the score level of Lactobacillus bacteria concentration in saliva
was found after 14 days post-intervention (p=0.011). While Aloe vera juice did not significantly
decreased the score level of Streptococcus mutans (p=0.734). Neither allergy nor side effects of
daily drinking of Aloe vera juice for 14 consecutive days was detected.
Conclusion: Our finding revealed anti-bacterial effect of Aloe vera juice against Lactobacillus
bacteria concentration in Thai healthy volunteers without any side effects.
Key words: aloe vera; microbiology; saliva
31
MAY 20th-21st, 2015
TRI-UNIVERSITY CONSORTIUM
P-4
Infection of a Periodontal Pathogen, Porphyromonas gingivalis, Triggers Cardiac
Rupture of Infarcted Myocardium in Mice
Yuka Shiheido*, Yasuhiro Maejima, Jun-ichi Suzuki, Norio Aoyama,
Makoto Kaneko, Yuichi Izumi, and Mitsuaki Isobe
Tokyo Medical and Dental University, Tokyo, Japan
Objective: A growing body of evidence suggests a strong association between periodontal disease
and coronary artery diseases. However, the effects of periodontal disease on the pathophysiology
of myocardial infarction (MI) remain unknown. Here, we show that the infection of periodontal
pathogens also affects the vulnerability of the myocardium after MI.
Materials and Methods: C57BL/6J male mice were split into 3 groups. Before and after coronary
artery ligation, each group was injected with one of the following bacteria or substance:
Porphyromonas gingivalis (P.g.), Aggregatibacter actinomycetemcomitans (A.a.: a periodontal
pathogen), or phosphate buffered saline (PBS).
Results: Observation of the mice lasted for 14 days after MI. A significant increase of mortality due
to cardiac rupture was observed 5 days after MI in the P.g.-injected mice compared to the
A.a.-injected or PBS-injected mice (P.g. [n=19] vs PBS [n=12] 42.1 vs 0%, p < 0.05, A.a. [n=7] vs
PBS [n=12] 14.2 vs 0%). H2O2 release from the infarcted myocardium significantly increased in
the P.g.-injected MI mice compared to the PBS-injected MI mice (P.g.[n=6] vs PBS[n=6]: 31.0±9.1
vs 6.3±3.4 pmol). The activity of MMP-9 in the myocardium was much higher in the P.g.-injected
MI mice (2.9 ± 0.6 fold, n=7) than in the PBS-injected MI mice(n=7). The level of activated Bax
in the myocardium also significantly increased in the P.g.-injected MI mice (1.7±0.1 fold, n=5)
compared to the PBS-injected MI mice (n=5). Consistently, the number of TUNEL-positive
cardiomyocytes in the infarcted myocardium was greater in the P.g.–injected MI mice than in the
PBS-injected MI mice. The plasma levels of HMGB-1 were relatively higher in the P.g.–injected
MI mice than in the PBS-injected MI mice.
Conclusion: Infection with P.g. during MI plays a detrimental role in inducing both apoptosis and
necrosis of cardiomyocytes, thereby provoking cardiac rupture.
Key words: cardiac rupture; porphyromonas gingivalis
32
TRI-UNIVERSITY CONSORTIUM
MAY 20th-21st, 2015
P-5
Transcriptomic Alteration of Cultured Dental Mesenchymal Cells
Yunfei Zheng
Peking University School and Hospital of Stomatology, Beijing, China.
Objective: Dental mesenchymal cells (DMCs) differentiate into dentin-secreting odontoblasts and
are utilized in the majority of tooth regeneration studies to produce an entire tooth organ. An in
vitro culture platform of DMCs is useful in generating an adequate quantity of cells for experiments
and regenerative therapy. However, the influence of in vitro culture on the transcriptome of DMCs
remains unclear.
Materials and Methods: DMCs from developing molar germs in embryonic day 14.5 (E14.5)
mouse embryos were isolated and designated as P0. The cells were then subcultured in standard
medium and passaged once they reached 90% confluence, with the first-passage culture
designated as P1 and the second-passage as P2. Illumina-based high-throughput sequencing was
used to obtain the transcriptome profiles of P0, P1 and P2 cells. The cell proliferation and
osteogenic potential of DMCs were assessed using Cell counting kit 8 and Alizarin Red S staining.
Results: Hierarchical clustering analysis and principal components analysis reveal an overall
transcriptional similarity between the first and second passages that differed significantly from
freshly obtained cells. Following in vitro culture, the biological processes of cell adhesion,
chromatin organization, cell differentiation and development are significantly altered. Components
of signaling pathways, including p53, transforming group factor β/bone morphogenetic protein
(TGFβ/BMP), Hedgehog, and Wnt, as well epigenetic regulators are involved. Furthermore, the
cell proliferation and osteogenic potential of cultured dMCs is also impaired.
Conclusion: Attempts to cultivate DMCs in vitro led to significant modification of cell
transcriptome and impaired cell potentiality.
33
MAY 20th-21st, 2015
TRI-UNIVERSITY CONSORTIUM
P-6
In-office Bleaching Gel with 35% Hydrogen Peroxide Enhanced
Biofilm Formation of Early Colonizing Streptococci on Human
Enamel
Suttinee Ittatirut, Panida Thanyasrisung* and Oranart Matangkasombut
Faculty of Dentistry, Chulalongkorn University, Bangkok, Thailand
Objective: To compare the effects of 25% and 35% hydrogen peroxide in-office bleaching systems
on surface roughness and streptococcal biofilm formation on human enamel.
Materials and Methods: Enamel specimens (3x3x2 mm3, n=162) from human permanent teeth
were randomly divided into 3 treatment groups (n=54 each): (1) control, (2) bleached with 25%
hydrogen peroxide (Zoom2TM), and (3) bleached with 35% hydrogen peroxide (BeyondTM). The
enamel surface roughness was measured by a profilometer before and after treatments.
Subsequently, the treated enamel specimens were randomly placed into 3 subgroups (n=18 each)
and incubated with: (1) trypticase soy broth control, (2) Streptococcus mutans culture and (3)
Streptococcus sanguinis culture for 24 hours. Biofilm formation was quantified by crystal violet
staining. The biofilm structure on three specimens from each group was visualized by scanning
electron microscopy. Data were analyzed by Kruskal-Wallis and Man-Whitney U tests with
Bonferroni corrections. Significance level was set at p<0.05.
Results: Both bleaching systems significantly reduced enamel surface roughness comparing to the
control group (p<0.001), but there was no difference between the two treatment groups. Remarkably,
Streptococcus sanguinis biofilm formation was significantly higher on enamel specimens bleached
with 35% hydrogen peroxide than other treatments (p<0.001), but was lower on those bleached
with 25% hydrogen peroxide (p<0.001). In contrast, no difference in Streptococcus mutans
biofilm formation was observed among the three treatment groups.
Conclusion: Both 25% and 35% hydrogen peroxide caused similar degrees of reduction in enamel
surface roughness. Nevertheless, bleaching with 35% hydrogen peroxide appeared to markedly
promote Streptococcus sanguinis biofilm formation.
Key words: biofilm formation; enamel; hydrogen peroxide; in-office bleaching; Streptococcus
mutans; Streptococcus sanguinis
34
TRI-UNIVERSITY CONSORTIUM
MAY 20th-21st, 2015
P-7
Elevated Platelet Activation in Generalized Aggressive Periodontitis
Yalin Zhan*, Xin Zhang, Xian’e Wang, Xiaojun Sun, Ruifang Lu, Jianxia Hou,
Huanxin Meng
Department of Periodontology, Peking University School and Hospital of
Stomatology, Beijing, China
Objective: Multiple studies have shown that periodontitis may be a risk factor for cardiovascular
diseases (CVD), and platelet activation play an important role in the development of atherosclerosis
and subsequent CVD. Oral bacteria and systemic inflammation may contribute to platelet activation.
In patients with periodontitis, ulcerated pocket epithelium may facilitate bacteria entrance into the
circulation and bacteremia occur regularly, which underlie chronic production of pro-inflammatory
mediators. This study aimed to investigate platelet activation in generalized aggressive
periodontitis (GAgP) patients.
Materials and Methods: 45 patients with GAgP and 60 healthy subjects were enrolled into the
study. All subjects received periodontal and hematological examinations. Calprotectin levels in
the gingival crevicular fluid (GCF) and plasma were measured by enzyme-linked immunosorbent
assay.
Results: Platelet count (PLT) was significantly lower in GAgP patients compared with healthy
subjects (198.00 (170.00-236.50)×109/L vs. 237.00 (189.75-269.00) ×109/L, p<0.05).
In accordance with PLT, large cell ratio (PLCR) and mean platelet volume (MPV) were also
decreased in patients compared with that in controls, although not reached significant difference
(0.19 (0.17-0.23) % vs. 0.21 (0.18-0.26) %, 9.10 (8.70-9.55) fL vs. 9.20 (8.75-9.70) fL).
Calprotectin levels in GCF and plasma were significantly higher in patients with GAgP compared
with healthy subjects (amount in GCF 3903.18 (1401.92-6934.72) ng vs. 89.19 (64.21-181.84) ng,
p<0.001; concentration in GCF 2244.29 (536.65-3172.26) μg/mL vs. 694.12 (393.49-1020.27) μg/
mL, p=0.004; concentration in plasma 2.04 (1.31-3.30) mg/L vs. 1.60 (1.17-2.07) mg/L, p= 0.013).
In GAgP group, partial correlations was found between the GCF calprotectin amount and PLT
after adjusting for age, gender and BMI index (r = -0.366, p= 0.039).
Conclusion: The patients with GAgP increased calprotectin levels in GCF and plasma, developed
severe inflammation, while PLT, PLCR and MPV value was found to be decreased. Interaction
with leukocytes, activated platelets migrate within and through the vasculature to inflammatory
sites and were intensely consumed. It may provide evidence that periodontitis is associated with
increased platelet activation. Since platelet activation contributes to the development of
atherosclerosis and subsequent CVD, it may partly explain the mechanism of periodontitis on
pathogenesis of CVD.
Key words: atherosclerosis; calprotectin; periodontitis; platelet activation
35
MAY 20th-21st, 2015
TRI-UNIVERSITY CONSORTIUM
P-8
Human Cementoblasts Response to IL-1beta
Ruchanee Ampornaramveth1*, Huynh Cong Nhat Nam1,2, Prasit Pavasant2,3
DRU in Oral Microbiology, Microbiology department, Faculty of Dentistry
Chulalongkorn University, Bangkok, Thailand
2
Mineralized Tissue Research Unit, Faculty of Dentistry Chulalongkorn University,
Bangkok, Thailand
3
Department of anatomy, Faculty of Dentistry Chulalongkorn University, Bangkok, Thailand
1
Objective: Cementum is a heterogeneous mineralized tissue that covers the entire root surface.
Bone and cementum share a couple of characteristics such as structure and pattern of gene expression.
The objective of our study is to isolate and characterize human cementoblasts and test their
response to inflammatory cytokine, IL-1beta.
Materials and Methods: Human cementoblasts were isolated from extracted healthy third molar
by sequential collagenase digestion. The cells at 120 min fraction show the strongest expression of
BSP. ALP was generally expressed at low level in every fraction.
Results: Human cementoblasts expressed a remarkable level of both IL-RI and IL-RII. Treatment
with IL-1beta remarkably up-regulated RANKL in these cells. No change in OPG expression was
observed.
Conclusion: IL-1beta stimulated RANKL in human cementoblasts. Further investigations are
ongoing.
Key words: human cementoblasts; IL-1beta; OPG; RANKL
36
TRI-UNIVERSITY CONSORTIUM
MAY 20th-21st, 2015
P-9
Denture Stability of Mandibular Implant Overdentures with Locator
Attachments
Ken Oda*, Manabu Kanazawa, Shin Takeshita, Mariko Tanoue, Yuri Omura,
Kaidiliya Yalikun, Anna Miyayasu, and Shunsuke Minakuchi
Gerodontology and Oral Rehabilitation, Tokyo Medical and Dental University,
Tokyo, Japan
Objective: In the case of mandibular implant overdenture (IOD), rotational denture movement has
a negative effect on perceived chewing ability. Through three-dimensional finite element analysis,
3 implants prevent the rotation. However, no detailed information was reported about the actual
denture movement of mandibular IOD. The aim of this study was to evaluate denture movement
of mandibular IOD anchored by different numbers of implants.
Materials and Methods: An edentulous mandibular model with silicone artificial mucosa was
fabricated. Five implant replicas were placed in the anterior midline, bilateral lateral incisor
regions and bilateral canine regions, which made it possible to change implant number on the
same mandibular model. Five mandibular overdentures were fabricated. Five metal caps were
incorporated to the intaglio surface of the each overdenture. Three implant positions were
prepared; 1-IOD (anterior midline), 2-IOD (lateral incisor regions), 3-IOD (the midline and canine
regions). Vertical loads of 50N were applied on the mid-anterior region or right first molar region.
The displacement at the left distal edge of the denture base on loading at the right molar region,
and at the both distal edge of the denture base on loading at the mid-anterior region were measured
using a movement sensor. Statistical comparison was made using a one-way ANOVA and Tukey’s
test (p<0.05).
Results: On loading at the mid-anterior region, 3-IOD showed significantly smaller movement
than 2-IOD at the both sides, 1-IOD movement was significantly smaller than 2-IOD at the right
side, and 3-IOD showed significantly smaller movement than 1-IOD at the left side. No significant
difference was noted on loading at the right first molar region.
Conclusion: Within the limitations of this study, 3-IOD showed the minimum movement, and
2-IOD appeared to rotate easily compared to the 1-IOD.
Key words: denture movement; implant number; implant overdenture
37
MAY 20th-21st, 2015
TRI-UNIVERSITY CONSORTIUM
P-10
Disparities in Tooth Loss and Prostheses Obtaining Among Thai
Elderly
N. Bunchuansakul, N. Navapakpilai, C. Wansudon, Tewarit Somkotra*
Faculty of Dentistry, Chulalongkorn University, Bangkok, Thailand
Objective: To determine the association of number of remaining teeth and prostheses obtaining
among Thai elderly with underlying determinants under the universal coverage in its health care
system
Materials and Methods: The data to perform analyses were conducted from the nationally
representative older adults (aged 50 years and over) survey, namely Survey of Older Person in
Thailand (N= 56002). Data of 30427 representative Thai elderly (aged 60 years and over) were
analysed. The distribution of reported number of remaining teeth < 20 and prostheses obtaining
among Thai elderly were revealed. Multivariate logistic regression was employed to determine the
underlying determinants and their associations with reported number of remaining teeth <20 and
prostheses obtaining.
Results: There are disparities in remaining teeth <20 across age-groups, sex, socioeconomic
status (household living standard quintiles, educational attainment), health-related behaviors, social
capital, and geographic characteristic. That is, elderly of older age group compared to younger
counterpart, female, lower level of educational attainment, lower socioeconomic status and of
those with low level of social capital has higher proportion of remaining teeth <20 without
prostheses obtaining (p<0.001). Multivariate analysis demonstrates that certain demographic-,
socioeconomic-, and geographic characteristics are particularly significant associated with disparities
in remaining teeth <20 and prostheses obtaining among Thai elderly (p<0.05).
Conclusion: There are persistence of disparities in tooth loss and protheses obtaining among Thai
elderly despite universal dental care in its health care system
Key words: disparities; prosthesis obtaining; Thai elderly; tooth loss
38
Poster Presentation
Group 2 P11-P21
MAY 20th-21st, 2015
TRI-UNIVERSITY CONSORTIUM
P-11
Oculofaciocardiodental Syndrome: Novel BCOR Mutations
and Expression in Dental Cells
Thunyaporn Surapornsawasd1*, T. Ogawa1,2, M. Tsuji1 and K. Moriyama1,2
Maxillofacial Orthognathics, Graduate School, Tokyo Medical and Dental University,
Tokyo, Japan
2
Hard Tissue Genome Research Center, Tokyo Medical & Dental University, Tokyo, Japan
1
Objective: Oculofaciocardiodental (OFCD) syndrome is a rare X-linked dominant condition.
Mutations in BCOR have been described as causal in OFCD syndrome. Almost all BCOR
mutations result in premature termination codons (PTCs); therefore, nonsense-mediated mRNA
decay (NMD) might have an important role in pathogenesis. The purpose of this study was to
identify BCOR mutations in two OFCD patients, if it present, and to clarify the pathogenesis of
radiculomegaly using one OFCD patient’s pulp and periodontal ligament (PDL) cells.
Materials and Methods: Genomic DNAs extracted from buccal swabs of the two OFCD patients
and their parents were used in genetic analysis. In addition, PDL and pulp tissue were harvested
from different sites of the extracted first premolar of one affected patient and then cultured. After
confirmed cell characteristic and BCOR expression, we performed an analysis of NMD, RNA
stability and cell proliferation on these two cell types.
Results: In our genetic analysis, two novel BCOR mutations were found, nonsense mutation,
c.*4794G4A (p.W1598*) and frameshift mutation, c.3668delC (p.S1223Wfs*15). According to
cellular analysis, BCOR expression was normal in pulp but reduced in PDL cells, which is
consistent with the higher rates of NMD in PDL cells. The mutant PDL cells had unstable mutant
transcripts and proliferated faster than did wild-type cells, but mutant pulp cells appeared normal
by these measures.
Conclusion: In summary, the nonsense and frameshift mutations, which introduce PTCs, were
found to contribute to OFCD syndrome in our two patients. Furthermore, in PDL cells, the
mutation resulting in a PTC corresponded to greater NMD, unstable mutant transcripts and
increased cell proliferation, which may contribute to hyperactive root formation.
Key words: nonsense-mediated mRNA decay; oculofaciocardiodental syndrome; radiculomegaly;
X-linked dominant
40
TRI-UNIVERSITY CONSORTIUM
MAY 20th-21st, 2015
P-12
Mutations in the PAX9 gene associated with Non-syndromic
Oligodontia
Haochen Liu*, Songwei Wong, Hailan Feng
Peking University School and Hospital of Stomatology, Beijing, China
Objective: Congenital tooth agenesis is one of the most common developmental anomalies in
human and it may contribute to masticatory dysfunction, speech alteration, aesthetic problem and
malocclusion. The paired-domain transcription factor PAX9 plays a critical role in tooth development,
as heterozygous mutation of PAX9 is associated with non-syndromic tooth agenesis. The aim of
the study was to search for PAX9 mutation in 120 patients with nonsyndromic tooth agenesis.
Materials and Methods: In a large cohort of 120 patients with non-syndromic tooth agenesis, 4
exons of the PAX9 gene have been sequenced. All the patients were congenital absence of six or
more permanent teeth excluding third molar.
Results: 11 mutations in PAX9 were identified in 120 unrelated patients with tooth agenesis.
9 of them (c.140G>C, c.167T>A, c.332G>C, c.194C>A, c.271A>T, c.146delC, c.185_189dup,
c.256_262dup, c.592del G) are novel mutation. The 11 mutation consists of 4 missense mutations,
2 nonsense mutations and 5 frameshift mutations. All the mutation were in the exon 2 of PAX9,
suggesting that exon 2 a notable hot spot mutation region in the PAX9 gene. Phenotypic analysis
shows that the maxillary first molar is the most common missing tooth in patients with PAX9
mutation; the maxillary canine was rarely involved.
Conclusion: Our results show that PAX9 mutation accounted for 9.12% of tooth agenesis cases.
These findings greatly expand the mutation spectrum of tooth agenesis and suggest that PAX9 can
be regarded as a marker gene for tooth agenesis.
Key words: mutation; non-syndromic oligodontia; PAX9 gene
41
MAY 20th-21st, 2015
TRI-UNIVERSITY CONSORTIUM
P-13
Exome Sequencing Identified a Novel PCCB Mutation in a Thai
Patient with Propionic Acidemia
Thantrira Porntaveetus1*, Chalurmpon Srichomthong2,3, Kanya Suphapeetiporn2,3,
and Vorasuk Shotelersuk2,3
Department of Physiology, Faculty of Dentistry, Chulalongkorn University,
Bangkok, Thailand
2
Center of Excellence for Medical Genetics, Department of Pediatrics, Faculty of Medicine,
Chulalongkorn University, Bangkok, Thailand
3
Excellence Center for Medical Genetics, King Chulalongkorn Memorial Hospital, the Thai Red
Cross Society, Bangkok, Thailand
1
Objective: Propionic acidemia (PA) is an inborn error of metabolism, caused by mutations in
either the PCCA or PCCB gene, leading to mitochondrial accumulation of propionyl-CoA and its
by-products. It has been shown that mutations in either the PCCA (chromosome 13q32) or PCCB
(chromosome 3q21-q22) genes encoding alpha or beta subunits of the PCC enzyme, respectively,
can cause propionic acidemia. PCCA mutations have been identified in a small number of Thai
patients whereas PCCB mutations have never been reported in Thailand. In this study, we aim to
identify the disease-causing mutation in a six-year-old Thai boy with PA.
Materials and Methods: PA was diagnosed by newborn screening using tandem mass
spectrometry (MS/MS) and urine organic acid analysis using gas chromatography and mass
spectrometry. Whole Exome Sequencing (WES) was used to identify the disease-causing mutation
of PA. The presence of the identified variant was confirmed by Sanger sequencing.
Results: The proband was born to consanguineous parents and presented with fusion of primary
mandibular incisors. WES revealed a novel homozygous frameshift 22 insertion (c.379_380insA;
p.T127NfsX160) in the PCCB gene. These have never been previously reported. His parents were
heterozygous for the mutation. It was absent in 100 exome Thai controls.
Conclusion: We identified a novel homozygous frameshift insertion, c.379_380insA:p.
T127NfsX160, in the PCCB gene associated with PA in a Thai family. The mutation was expected
to result in unstable mRNA. It is possible that PCCB mutation could lead to abnormal tooth formation.
This study was supported by the Higher Education Research Promotion and National Research
University Project of Thailand, Office of the Higher Education Commission (WCU-58-024AS), the Ratchadapiseksomphot Endowment Fund (RES560530177-HR, RES560530246-AS,
RES560530253-AS), Chulalongkorn University, and the Thailand Research Fund (RTA5680003,
TRG5780209).
Key words: mutation; PCCB; propionic academia; Thai; whole exome sequencing
42
TRI-UNIVERSITY CONSORTIUM
MAY 20th-21st, 2015
P-14
New DLX3 Mutation Delays Senescence in Tricho-Dento-Osseous
Syndrome
Na Zhao*, Dong Han, Haochen Liu, Yue Li, Yixiang Wang, Hailan Feng
Peking University School and Hospital of Stomatology, Beijing, China
Objective: Mutation of the distal-less gene (DLX3) is closely associated with Tricho-Dento-Osseous syndrome, which features abnormal hair, teeth and increased cranial bone density. Here, a
novel DLX3 (Q178R) mutation was identified in a Chinese TDO patient. Alveolar bone-derived
mesenchymal stem cells collected from this TDO patient were cultured to investigate why and how
this novel DLX3 mutation affects BMSC osteogenesis.
Materials and Methods: BMSCs from the TDO patient (TDO-BMSCs) and gender- and
age-matched health donors (CON-BMSCs) were isolated and cultured from alveolar bone. The
proliferation and apoptosis properties were investigated by clonogenesis, CCK-8 and annexin
V-FITC/PI assays. The osteogenesis was evaluated using ALP histochemistry and activity assay,
Alizarin red staining, real-time PCR and western blot. Meanwhile, the aging process was tested by
β-galactosidase staining, flow cytometry, real-time PCR and western blot.
Results: The clonogenesis, CCK-8, apoptosis, and osteogenesis assays showed that the BMSCs-TDO
had higher self-renewal and proliferation, and higher anti-apoptosis activity but lower osteogenesis
activity than CON-BMSCs. Surprisingly, senescence assays results showed that TDO-BMSCs
presented a lower aging rate and higher stemness property than CON-BMSCs. These results
indicated that TDO-BMSCs had a longer life span and would produce more BMSC daughter cells
to perform the osteogenesis, thereby resulting in a gradual accumulation of cranial bone formation,
finally leading to a classical clinical manifestation of TDO syndrome.
Conclusion: In this study, we provide a new explanation of the underlying mechanism from an
aging perspective. We conclude that the novel DLX3 mutation caused the increased cranial bone
density of this TDO patient by altering BMSC senescence and osteogenesis. The higher bone
density is due to a cumulative osteogenic effect resulting from higher self-renewal, proliferation
and anti-apoptosis activity as well as a longer life span of the TDO-BMSCs.
Key words: BMSCs; DLX3; osteogenesis; senescence; TDO syndrome
43
MAY 20th-21st, 2015
TRI-UNIVERSITY CONSORTIUM
P-15
A Retrospective Study of Jaw Cysts in Thai Population
Risa Chaisuparat1*, B. Wangsrimongkol2, A. Pengprecha2, and S. Katseemool2,
Department of Oral pathology, Faculty of Dentistry, Chulalongkorn University,
Bangkok, Thailand,
2
Undergraduate student, Faculty of Dentistry, Chulalongkorn University,
Bangkok, Thailand
1
Objective: The aim of this retrospective study was to analyze the demographic information and
clinico-radiographic features of the patients with jaw cysts in a group of Thai population.
Materials and Methods: Pathology reports from the department of Oral Pathology, Faculty of
Dentistry, Chulalongkorn University from 2003 to 2012 were reviewed. Data of cases diagnosed
with jaw cysts including age, gender, lesion location, signs and symptoms, radiographic features,
and histologic diagnoses was recorded. Descriptive data analysis was performed using the Excel
version 2013.
Results: One thousand two hundred and twenty-five cases of total 6,265 cases were cystic lesions
(19.55%). Odontogenic cysts accounted for 93.31% of the jaw cysts. Radicular cyst was the most
prevalent type of the jaw cysts (34.53%), followed by dentigerous cyst (27.92%), and odontogenic
keratocyst (15.18 %), respectively. The most common type of odontogenic cyst was radicular cyst
(36.19%) and the most common type of non-odontogenic cyst was nasolabial cyst (37.5%). The
mean age of patient with jaw cysts was 19 years. The jaw cysts were slightly more prevalent in
males (51.84%) than in females (48.16%). The most frequent occurring site of the jaw cysts was
the posterior mandible (34.69%). The majority of jaw cyst patients complained of painless
swelling (31.35%). The most commonly reported radiographic finding was unilocular radiolucency
(75.18%) with well-defined margin (38.04%).
Conclusion: The findings of this study indicate that the jaw cysts are relatively common lesions.
Odontogenic cysts outnumber non-odontogenic cysts in incidence. Frequency, demographic and
clinical characteristics of the jaw cysts are comparatively similar to previous studies with some
minor differences.
Key words: jaw cyst; non-odontoogenic cyst; odontogenic cyst
44
TRI-UNIVERSITY CONSORTIUM
MAY 20th-21st, 2015
P-16
Exosomal TGFBI Promote Cervical Metastasis in OSCC Patients
Xiaowen Zheng*, Weipeng Jiang, Feng Chen, Jiuxiang Lin
Peking University School and Hospital of Stomatology, Beijing, China
Objective: To explore the mechanism of cervical lymph node metastasis promoted by salivary
exosomes in oral squamous cell carcinoma (OSCC) patients
Materials and Methods: Collect the salivary samples of 10 healthy people, 10 OSCC patients
with cervical lymph node metastasis (OCM) and 10 OSCC patients without cervical lymph node
metastasis (OUCM). Extract the salivary exosomes of collected samples and use electron
microscopy to observe the shape and size of exosomes. Use mass spectrum method to identify
proteins in exosomes. GO and pathway analysis are used to screening specific proteins between
OCM and OUCM.
Results: There are about more than 1000 proteins in salivary exosomes of OCM and OUCM
respectively. Among these, OCM have higher expression of exosomal proteins. Through GO and
pathway analysis, we find one protein that present great difference between OCM and OUCM
called transforming growth factor-beta-induced protein (TGFBI). This exosomal protein is related
to cell adhesion and cancer metastasis, and its expression profiles are higher in OCM. Molecular
biology and cytology experiments verified that exosomal TGFBI play an important role to promote
cervical lymph node metastasis in OSCC patients.
Conclusion: Salivary exosomes have the characteristics of long distance transport. Their content
proteins and microRNAs may play an important role in the development of diseases. In this
research, we suggested exosomal protein (TGFBI) may contribute to promoting cervical metastasis
in OSCC patients.
Key words: exosomes; metastasis; OSCC; TGFBI
45
MAY 20th-21st, 2015
TRI-UNIVERSITY CONSORTIUM
P-17
Underestimated PTCH1 Mutation Rate in Sporadic Keratocystic
Odontogenic Tumors
Jiafei Qu1*, Feiyan Yu1, Yingying Hong1, Yanyan Guo1, Lisha Sun2, Xuefen Li2,
Jianyun Zhang1, Heyu Zhang2, Ruirui Shi2, Feng Chen2 and Tiejun Li1
Department of Oral Pathology, Peking University School and Hospital of
Stomatology, Beijing, China,
2
Central Laboratory, Peking University School and Hospital of Stomatology, Beijing, China
1
Objective: Keratocystic odontogenic tumors (KCOTs) are benign cystic lesions of the jaws
that occur sporadically in isolation or in association with nevoid basal cell carcinoma syndrome
(NBCCS). The protein patched homolog 1 gene (PTCH1) is associated with NBCCS development
and tumor genesis associated with this syndrome. However, previous studies have revealed that
more than 85% of syndromic KCOTs and less than 30% of sporadic KCOTs harbor PTCH1
mutations. The significantly lower PTCH1 mutation rates observed in sporadic KCOTs suggest
that they serve a minor role in pathogenesis. We aimed to discern the importance of PTCH1
mutations in sporadic KCOTs.
Materials and Methods: PTCH1 mutational analysis was performed with 19 new sporadic KCOT
cases by direct sequencing of epithelial lining samples separated from fibrous capsules. Using this
approach, we further reexamined 9 sporadic KCOTs that were previously reported to lack PTCH1
mutations by our group.
Results: Nineteen PTCH1 mutations were detected in patient samples from 16/19 new cases
(84%)—all these mutations were absent in fibrous tissues and peripheral blood specimens from
the same patients. We also identified four PTCH1 mutations in 3/9 patients (33%) that were
previously undetected.
Conclusion: These data indicated that PTCH1 mutations occur in sporadic KCOTs at a higher rate
than previously suspected, owing to the masking effects of the attached stromal tissues in the test
samples. These results suggest that the PTCH1 gene plays a significant role in the pathogenesis of
sporadic KCOTs, which is comparable to that observed in NBCCS patients.
Key words: keratocystic odontogenic tumors; mutation; PTCH1
46
TRI-UNIVERSITY CONSORTIUM
MAY 20th-21st, 2015
P-18
Long-term Stability of Cutaneous and Muscle Pain Measures
in Females
Kanokporn Bhalang1*, William Maixner2, Gary D. Slade2
Department of Oral Medicine, Faculty of Dentistry, Chulalongkorn University,
Bangkok, Thailand
2
University of North Carolina, Chapel Hill, North Carolina, United States
1
Objectives: To evaluate temporal stability of pressure pain thresholds, C-fiber mediated heat pain,
ischemic pain, and the temporal summation of C-fiber mediated heat pain over a two-year period
in 156 females assessed at one or several anatomical sites.
Materials and Methods: Assessments were conducted three times (baseline/annual visit Year 1/
annual visit Year 2) with each session separated by approximately one year. Pearson’s correlation
coefficients were computed as measures of temporal stability. Intra-class correlation coefficients
(ICC) was calculated for each pair of measurements to determine the proportion of variance that is
due to between-subject effects. Paired t-test was performed to compare the differences in the mean
values obtained across sessions.
Results: Study participants were aged 18-34 years at enrollment. Measurements were recorded for
202 participants at enrollment and one annual follow-up visit; 156 had mesurements at enrollment
and two annual follow-up visits. Most measures showed statistically significant within-subject
correlations across the two-year observational period. For a given stimulus modality, the stability of
threshold values was somewhat lower (ρ≈0.51-0.70) than that of tolerance values (ρ≈0.620.74). C-fiber mediated heat pain tolerance showed the greatest within-subject temporal stability.
Mechanical, ischemic, and temporal summation of C-fiber mediated heat pain measures show
moderate temporal stability (ρ≈0.43-0.68). Pressure pain threshold on masseter muscles and
ischemic pain tolerance significantly decreased over time.
Conclusions: These findings demonstrate the long-term within person stability of C-fiber heat
pain tolerance in assessing pain sensitivity and also validate the use of this measure in longitudinal
studies.
Keywords: females; pain measures; stability
47
MAY 20th-21st, 2015
TRI-UNIVERSITY CONSORTIUM
P-19
Dose Sarcopenia Affect the Strength of Tongue Muscle and Supra
Hyoid Muscle?
Nami Machida*, Haruka Tohara, Shunsuke Minakuchi
Department of Gerontology and Gerodontology Tokyo Medical and Dental
University
Objective: Sarcopenia is outlined as a decreasing of skeletal muscle mass and strength with aging.
We conducted the study if sarcopenia affects on the strength of tongue muscle and supra hyoid
muscles in elderly.
Materials and Methods: 71 healthy elderly and 96 frail elderly were enrolled in this study.
According to report of the Asian Working Group for Sarcopenia, 96 elderly were divided into 2
groups, sarcopenia group (sarco) and non-sarcopenia group (non-sarco). There was no sarcopenia in
healthy elderly group. The tongue pressure and the jaw-opening force that represents the strength
of supra hyoid muscles were examined and compared.Deta was analyzed using ANOVA and
bonferroni for post hoc analysis.
Results: Tongue pressure: In men there are significant differences between 3groups and each
groups (p<0.05). In women, significant differences were also found between 3 groups, healthy and
(sarco),(non-sarco) and (sarco) (p<0.05).
The jaw-opening force:There are significant differences between 3groups, healthy and (sarco),
(non-sarco) and (sarco) (p<0.05). In women, There was no a significant difference between 3
groups.
Conclusion: Since tongue pressure of (sarco) was significantly lower than (non-sarco) in both
of men and women, tongue muscle can be affected by sarcopenia. Furthermore, tongue pressure
of men could be easily affected by age because tongue pressure of (non-sarco) was significantly
lower than healthy. This result suggested that the aging effect of tongue muscle possibly had
gender difference. The jaw-opening force of (sarco) was significantly lower than (non-sarco) in
men. However, there was no significant difference in women. The strength of supra hyoid muscle
in women can be maintained with age. The effect of sarcopenia on the swallowing muscle can have
gender difference.
Key words: jaw-opening force; sarcopenia; tongue pressure
48
TRI-UNIVERSITY CONSORTIUM
MAY 20th-21st, 2015
P-20
Progesterone Attenuates Hyperalgesia of Inflamed TMJ through
Modulating Voltage-gated Sodium Channel 1.7 in Trigeminal
Ganglion
Rui-Yun Bi*, Yun Ding, Ye-Hua Gan
Peking University School and Hospital of Stomatology, Beijing, China
Objective: Temporomandibular disorders (TMDs) have the highest prevalence in women of
childbearing age, approximately twice than in men, which suggests that estradiol may play an
important role in TMD pain processing. But it’s hard to explain why women with TMD experience
some amelioration of pain during pregnancy, even though estrogen increasing throughout
pregnancy. Similar to estrogen, progesterone also increases dramatically and steadily during
pregnancy. Nav1.7 sodium channel plays a prominent role in pain perceptions, and our previous
study has shown that Nav1.7 in trigeminal ganglion (TG) involved in the hyperalgesia of inflamed
TMJ. Whether progesterone could modulate Nav1.7 in TG and reverse the estrogen effect remains
to be explored.
Materials and Methods: To examine the effects of both progesterone and inflammation on TMJ
pain, rats were divided into 5 groups, as follows: the control group, the sham-ovariectomized
group, and 3 groups of ovariectomized rats treated with 0μg, and 350μg, 700μg progesterone. To
examine the effects of both progesterone and estradiol on TMJ inflamed pain, rats were divided
into 4 groups, as follows: the control group, the 80μg estradiol group, the 700μg progesterone
group, and the group combined application with 80μg estradiol and 700μg progesterone. The
experimental groups were injected with 50 μl of complete Freund adjuvant into the bilateral TMJs
to induce inflammation on the tenth day of estradiol or progesterone treatment, and the control rats
were injected with vehicle. Head withdrawal threshold was used to evaluate pain behavior.
Real-time PCR and Western blot were used to evaluate Nav1.7 mRNA and protein expressions in
TG.
Results: Progesterone attenuated TMJ inflammation-induced trigeminal ganglionic Nav1.7 expression
in a dose-dependent manner. The progesterone receptor antagonist RU486 partially blocked the
effects of progesterone on mechanical threshold and Nav1.7 expression. Furthermore, progesterone
partial reversed the effects of estrogen on mechanical threshold and Nav1.7 expression.
Conclusion: Progesterone could attenuate hyperalgesia of inflamed TMJ through modulating
trigeminal ganglionic Nav1.7 and partially reverse the estrogen effect.
Key words: estradiol; Nav1.7; progesterone; temporomandibular joint
49
MAY 20th-21st, 2015
TRI-UNIVERSITY CONSORTIUM
P-21
Comparison Effects of Inflammation on Iodoacetate-induced
Osteoarthritis in TMJ and Knee Joint
Xue-Dong Wang1,2*, Ye-Hua Gan3, Yan-Heng Zhou1,2
Department of Orthodontics
Center for Craniofacial stem cell research and regeneration
3
Center for Temporomandibular Disorders and Orofacial Pain, Peking University School and
Hospital of Stomatology, Beijing, China
1
2
Objective: Osteoarthritis (OA) is a common degenerative joint disease that affects all synovial
joints, including TMJ and knee joint. There are differences in tissue origination, properties of the
articular cartilage and epidemiologic features of OA between the two joints. However, there are
few studies comparing the two joints in initiation or progression of OA. Inflammation has been
reported to play an important role in the progression of OA. The present study is to test the
hypothesis that inflammation affects OA differently between TMJ and knee joint.
Materials and Methods: Female Sprague-Dawley rats (8-week-old) were randomly assigned into
four groups, including control, inflammation, OA and enhanced inflammation+OA group, with
intraarticular injection of normal saline, Complete Freund’s Adjuvant (CFA), Monosodium
Iodoacetate (MIA) or MIA+CFA into the TMJ and knee joint, respectively. Immunohistochemical
(IHC) staining of Collagen II, CD68, MMP3 and iNOS were analysis. Osteoclasts in subchondral
bone were analysis by Tartrate-resistant acid phosphatase (TRAP) activity. Subchondral bone
resorption was evaluated by MicroCT.
Results: Inflammation increased the swelling of both joints but the swelling of knee lasted much
longer than TMJ. CFA injection induced evident inflammatory changes of the two joints, increased
expression of iNOS and CD68, but there was no evident cartilage or bone destruction. Synovial
inflammation aggravated cartilage degradation, including obvious loss of Toludine blue and
Collagen II staining. There were more CD68+ macrophages and TRAP+ osteoclasts in subchondral
bone of TMJ than knee joint in both control and OA group. HE staining and MicroCT showed
that subchondral bone erosion was more obvious in OA group of TMJ than knee joint. Enhanced
inflammation aggravated subchondral bone resorption and recruited more TRAP+ osteoclasts in
the two joints.
Conclusion: Inflammation could aggravate the cartilage degradation and subchondral bone erosion
induced by MIA in both TMJ and knee joint. The TMJ is more sensitive in subchondral bone
remodeling in reaction to the MIA than the knee joint.
Key words: inflammation; knee joint; osteoarthritis; temporomandibular joint
50
Poster Presentation
Group 3 P22-P32
MAY 20th-21st, 2015
TRI-UNIVERSITY CONSORTIUM
P-22
Evaluation of the Shear Bond Strength of Dental Porcelain to Zr–14Nb Alloy
with Low Magnetic Susceptibility
Yuka Kajima*, Atsushi Takaichi, Tohru Yasue, Hisashi Doi, Hidekazu Takahashi,
Takao Hanawa, Noriyuki Wakabayashi
Tokyo Medical and Dental University, Tokyo, Japan
Objective: The aim of this study was to investigate the bond strength of dental porcelain to
preheated Zr–14Nb alloy and compare its strength with that of titanium.
Materials and Methods: Cylindrical cast specimens of the Zr–14Nb alloy and titanium were
prepared. After sandblasting with Al2O3, the Zr–14Nb samples were subjected to a preheat
treatment at 700 °C for 5, 10, or 20 min and those without treatment were taken as control samples.
Dental porcelain was veneered on them; then, their bond strength (MPa) was evaluated by
performing shear bond tests (n=8/group) and the results were analyzed using ANOVA and Tukey’s
tests (p=0.05). The surface characteristics were evaluated by SEM-EDS and XRD; the elemental
distribution on the interface of metal-ceramics was determined by EDS.
Results: The samples subjected to the heat treatment for 5 min showed the highest mean bond
strength (43.7±5.9), which was significantly higher than that of titanium (35.3±3.5). On the preheated sample groups, white oxide layers, which were predominantly composed of monoclinic
zirconia, were formed, exhibiting a greater roughness than control samples; besides, on the interface
of the metal–ceramics, a greater diffusion range of Nb was observed than that found on the control
samples.
Conclusion: The preheat treatment performed on the Zr–14Nb substrates contributed to the
increase in the surface roughness and the diffusion of Nb, which enhanced the micro-retention
and chemical bonding, and improved the bond strength of Zr–14Nb and porcelain.
Key words: fixed dental prostheses; MRI artifact; porcelain; Zr–Nb alloy
52
TRI-UNIVERSITY CONSORTIUM
MAY 20th-21st, 2015
P-23
Silica Coating for Acrylic Denture Base Materials: The Effect of Solid Content
Concentration for Durability of Coating Layer
Taro Yoshizaki1*, Norihisa Akiba1, Masayuki Shimada2, Shunsuke Minakuchi1
Department of Gerodontology, Faculty of Dentistry, Tokyo Medical and
Dental University, Tokyo, Japan
2
Japan Nano Coat, Tokyo Japan
1
Objective: Hydrophilic surface modification prevents the adhesion of microbes to the acrylic
denture materials. Although denture coating materials (silica nanoparticles, TiO2 or silver nanoparticles
etc.) have some possibilities to prevent the pollution of denture, there still remain problems such as
durability of coating layer (Silica) or complication of coating method (silver or TiO2). The purpose
of this study is to investigate an appropriate solid content concentration of silica coating agent.
Materials and Methods: Heat-cure acrylic resin disks (GC, Acron) were divided into 5 groups:
control (treat with methanol), coated with silica coating material (Japan Nano Coat, Tokyo, solid
content concentration 0.25%, 0.5%, 0.75%, 1.0%). Durability of coating layer is evaluated by
contact angle measurement (VCA optima, ASC products) after brushing wear test (0, 200, 400,
600 cycles, 300gf). Statistically analyzed using a two-way analysis of variance between solid
content concentration, brushing cycles and contact angle. Statistical significance was set α=0.05
determine by SPSS.
Results: There were significantly difference between 0.5%, 0.75% groups and others in contact
angle measurement after brushing test (p<0.05). An appropriate solid content concentration would
be in 0.5~0.75% range. It showed high hydrophilicity (21.01±3.05, 25.98±5.75). There are no
statistically differences between 400 and 600 cycles of brushing wear test.
Conclusion: The appropriate concentration of silica nanoparticle (0.5-0.75%) enables to coat the
acrylic surface and its durability is to be stronger. It indicates the possibility that silica coating
can be used as a new method of protecting from pollution, and it may reduce risk of aspiration
pneumonia of elderly denture wearer. This coating agency has easy procedure (only dip and dry).
We can use it as a part of daily denture care.
Key words: antibacterial; denture base material; surface modification
53
MAY 20th-21st, 2015
TRI-UNIVERSITY CONSORTIUM
P-24
Three-five Minutes Ultrasonic Cleaning Reduce Residual Monomer
in Acrylic Resins
Chairat Wiwatwarrapan1*, T. Charasseangpaisarn1,2, and N. Leklerssiriwong1,3
Faculty of Dentistry, Chulalongkorn University, Bangkok, Thailand
Khon Kaen Hospital, Khon Kaen, Thailand
3
Nan Hospital, Nan, Thailand
1
2
Objective: Residual monomers in acrylic resins decrease their mechanical properties and are toxic
to the oral tissues. The current methods of reducing residual monomer are not clinically practical
due to the extensive chair-side time required. The aim of this study was to determine the effect
of ultrasonic cleaning time on the amount of residual methyl methacrylate monomer in three
auto-polymerized acrylic.
Materials and Methods: Thirty six disc-shaped auto-polymerized acrylic resin specimens of each
brand (Unifast Trad Ivory, Unifast Trad Pink, and Unifast III A2) were randomly divided into six
groups: Control, Positive control (immersion in 50°C water for 1 hour) and Ultrasonic treatment in
50°C water for 3, 5, 10, or 15 minutes. The residual monomer extraction procedure was performed
per ISO 20795-1:2013. High performance liquid chromatography (HPLC) was used to determine
the amount of residual monomer. The data were analyzed by one-way ANOVA and Tukey’s HSD.
Results: The amount of residual monomer in the positive control group and ultrasonic treatment
groups were significantly lower than that of the control group for each brand. The reduction in
residual monomers was not significantly different between the ultrasonic treatment in 50°C water
(3 minutes for Unifast Pink and 5 minutes for Unifast Ivory and Unifast III) groups and the
positive control group.
Conclusion: Ultrasonic treatment for 3–5 minutes reduced the amount of residual monomer in
auto-polymerized acrylic resin similar to immersion in 50°C for 1 hour; however less chair-time
was required.
Key words: acrylic resin; residual monomer; ultrasonic
54
TRI-UNIVERSITY CONSORTIUM
MAY 20th-21st, 2015
P-25
Effects of Surface Pre-reacted Glass-ionomer Fillers Contained
Toothpastes on Inhibition of Enamel Demineralization
Nakamura Keiki1*, Hamba H1, Nakashima S1, Sadr A2, Nikaido T1, Uo M3, Tagami J1
Department of Cariology and Operative Dentistry, Tokyo Medical and Dental
University, Tokyo, Japan
2
Department of Restorative Dentistry, University of Washington School of Dentistry, Seattle,
WA, United States
3
Department of Advanced Biomaterials, Tokyo Medical and Dental University, Tokyo, Japan
1
Objective: The purposes of this study were to evaluate the inhibitory effect of surface pre-reacted
glass-ionomer (S-PRG) fillers contained toothpastes on enamel demineralization using
micro-computed tomography (µCT) and micro particle induced X-ray emission (µPIXE).
Materials and Methods: Enamel with dentine blocks were prepared from bovine incisors. The
specimens were treated by one of the following agents; experimental tooth pastes containing 0-30
wt% S-PRG filler (S00, S01, S05, S10, S30), deionized water, and 950 ppm F (NaF) containing
toothpaste, twice a day for 4 days. All the specimens were then demineralized in an acetic buffer
solution (pH 4.5) for 3 days. Mean mineral loss (ML) of each specimen was calculated from
mineral density profiles obtained by µCT. The treated surface was investigated with scanning
electron microscopy (SEM) and µPIXE.
Results: The ML values of the S05, S10 and S30 groups demonstrated significantly smaller than
those of the S00, S01 and DW groups (p<0.05, one-way ANOVA and Tukey test). The S10 group
showed the most significantly inhibitory effect against demineralization. The S10 group also
demonstrated significantly smaller ML than the NaF group. The µPIXE examination in the S10
group showed the localization of strontium ions on the enamel surface.
Conclusion: Application of the toothpastes containing S-PRG filler to enamel surfaces
demonstrated inhibitory effect on enamel demineralization.
Key words: demineralization; dentine; fluoride; Micro-CT; strontium
55
MAY 20th-21st, 2015
TRI-UNIVERSITY CONSORTIUM
P-26
Wear Evaluation of Composite Resin and Antagonistic Tooth Enamel
with Using Focus Variation 3D Scanning Microscope
Yuki Naruse1*, Tomohiro Takagaki1, Naoko Matsui1, Takaaki Sato1, Toru Nikaido1,
Masaomi Ikeda2, Junji Tagami1
Cariology and Operative Dentistry, Graduate school, Tokyo Medical and
Dental University Tokyo, Japan
2
Clinical Oral Science, Department of Oral Health Care Sciences, Faculty of Dentistry,
Tokyo Medical and Dental University, Tokyo, Japan
1
Objective: The purpose of this study was to determine the wear properties of resin composite and
the antagonistic tooth enamel surface by means of impacting-sliding wear testing with using focus
variation 3D scanning microscope as a new method of wear evaluation.
Materials and Methods: Four different resin composites were used as the upper specimens
of impacting-sliding wear test (ISWT): Clearfil Mafesty ES-2 Premium (ES2), Estelite Asteria
(AST), Filtek Supreme Ultra (FSU), Venus Peal (VP) (n=6). 5mm hemispherical resin compoite
specimens were prepared on a jig and light cured with using a halogen light unit. Flattened (#1500
SiC paper) enamel of premolars were prepared as lower antagonistic specimens to simulate the
molar occlusal plane. After 24 h storage in distilled water at 37℃, the enamel specimens were
placed into a separate chamber of an ISWT machine together with an upper resin specimens. They
were subjected to impacting-sliding wear test. The upper hemispherical prepared specimens were
dropped on flattened enamel surfaces of premolars from a heighted 1mm with a load of 0.5MPa
and then horizontally slid for 1mm before being raised back the their original position with up to
50,000 multiple cycle in distilled water at 37°C. Volumetric loss was examined both on enamel
and composite resin by using Focus variation 3D scanning microscope (Infinite Focus, Alicona).
Results: ES2 showed a significantly higher volume loss of composite resin and enamel compared
to all the other groups (p<0.05,Wilcoxon rank-sum test with Bonferroni’s correction)
Conclusion: It was suggested that focus variation 3D scanning microscope is a useful device to
evaluate the volumetric loss after wear test of composite resin and tooth enamel.
Key words: tooth wear; two-body impact sliding test; 3D variation microscope
56
TRI-UNIVERSITY CONSORTIUM
MAY 20th-21st, 2015
P-27
Comparison of Mandibular Bone Micro-architecture Between MicroCT and
Cone-beam CT Images
Panmekiate Soontra*, Ngonphloy Noppawan, Charoenkarn Thanakom,
Faruangsaeng Thira, Pauwels Ruben.
Faculty of Dentistry, Chulalongkorn University, Bangkok, Thailand
Objective: To compare micro-architecture parameters of bone samples scanned using microCT to
those obtained by using CBCT.
Materials and Methods: A bone biopsy trephine (3mm*10mm) was used to remove 20 cylindrical
bone samples from the mandibular ridge of 20 autopsy mandibles. Samples were scanned using
microCT (µCT 35, SCANCO Medical, Brüttisellen, Switzerland) with a voxel size of 20µm and
CBCT (3D Accuitomo 170, J. Morita Mfg. Corp., Kyoto, Japan ) with a voxel size of 80µm.
All corresponding sample scans were aligned and tightly cropped. Image analysis was done using
ImageJ (BoneJ plugin) using the following parameters: Bone surface (BS/TV) and volume
density (BV/TV), fractal dimension (FracD), connectivity density, trabecular thickness (TbTh)
and spacing (TbSp), structure model index (SMI), plateness and skeleton analysis.
Correlation coefficients were calculated. Next, CBCT values were ‘calibrated’ using the slope of
the linear fit with the microCT. The mean error after calibration was calculated and normalised to
the SD of the microCT values.
Results: Correlation coefficients ranged between 0.05 (plateness) and 0.80 (BV/TV). Coefficients
were 0.64 or higher for BS/TV, BV/TV, FracD, TbTh, TbSp, and negative SMI and 0.52 or lower
for all other parameters. After calibration, the smallest normalised error was found for BV/TV
(0.48*SD). For other parameters, the error range was 0.58*SD to 2.10*SD.
Conclusion: Despite the overall correlation, this study demonstrates the large uncertainty
associated with using bone micro-architecture parameters on CBCT images. Although clinically
relevant parameter ranges are not available, the errors found in this study may be too high for most
parameters to be considered for clinical application.
Key words: bone; bone quality; computer--assisted image processing; cone-beam computed
tomography; microcomputed tomography
57
MAY 20th-21st, 2015
TRI-UNIVERSITY CONSORTIUM
P-28
Detection of Apical Periodontitis using Cone-Beam Computed
Tomography and Periapical Radiography
Shintaro Uraba1*, Kei Komatsu1, Arata Ebihara1, Naoto Obayashi2, Takashi Okiji1
Pulp Biology and Endodontics, Department of Oral Sciences, Graduate School
of Medical and Dental Sciences, Tokyo Medical and Dental University, Tokyo, Japan
2
Oral and Maxillofacial Radiology, Department of Oral Sciences, Graduate School of Medical
and Dental Sciences, Tokyo Medical and Dental University, Tokyo, Japan
1
Objective: Several limitations exist regarding the detection of apical periodontitis (AP) using
periapical radiography (PR), although it is the most common method for the radiographic
examination in endodontic treatment. Cone-beam computed tomography (CBCT) is expected to
overcome the shortcomings of PR in the detection of AP, whereas the diagnostic value of CBCT in
detecting AP remains fully investigated. The aim of this study was to evaluate the distribution of
lesions that could be detected in CBCT but not in PR, using clinical data.
Materials and Methods: This research was approved by Tokyo medical and Dental University
Ethics committee (No. 1010). The data of 97 roots from 64 endodontically treated teeth of 31
patients were used in this study. Inclusion criteria were as follows; for CBCT image, endodntically
treated teeth exist in the Field of View (FOV) besides the original objective teeth, and for those
teeth, PR images were also taken. Two examiners evaluated the prevalence of AP for both CBCT
and PR images. Sensitivity, specificity, positive predictive value (PPV) and negative predictive
value (NPV) were calculated. Also, data were compared among tooth types and statistically
analyzed by Steel-Dwass test (p<0.05).
Results: The number of lesions that were detected with CBCT, but not with PR, was 21 roots out
of 97 (21.7%). Sensitivity, specificity, PPV and NPV were 0.61, 0.98, 0.97 and 0.67, respectively.
There were no significant differences in the prevalence of undetectable AP between the tooth
types. Thirty three percent of the teeth examined as AP negative with PR, were judged AP positive
in CBCT.
Conclusion: The prevalence of AP may be underestimated by the use of PR compared with that of
CBCT, however, it may not differ in tooth types.
Key words: apical periodontitis; cone-beam computed tomography; periapical lesion; periapical
radiograph;
58
TRI-UNIVERSITY CONSORTIUM
MAY 20th-21st, 2015
P-29
Effect of Exposure Parameters and Voxel Size on Bone Structure Analysis in Conebeam CT
Ruben Pauwels*, Thira Faruangsaeng, Thanakom Charoenkarn, Noppawan
Ngonphloy, Soontra Panmekiate
Department of Radiology, Faculty of Dentistry, Chulalongkorn University,
Bangkok, Thailand
Objective: To evaluate the effect of exposure parameters and voxel size on bone structure analysis
in dental cone-beam computed tomography (CBCT).
Materials and Methods: Twenty cylindrical bone samples underwent CBCT scanning (3D
Accuitomo 170, J. Morita, Kyoto, Japan) using three combinations of tube voltage and mAs,
corresponding with a CT dose index of 3.4 mGy: 90 kV 62 mAs, 73 kV 108.5 mAs and 64 kV 155
mAs. Images were reconstructed with a voxel size of 0.080 mm. In addition, the 90kV scan was
reconstructed at voxel sizes of 0.125, 0.160, 0.200, 0.250 and 0.300 mm. The following
parameters were measured: bone surface (BS) and bone volume (BV) per total volume (TV),
fractal dimension, connectivity density, anisotropy, trabecular thickness and spacing, structure
model index (SMI), plateness, branches, junctions, branch length and triple points.
Results: For most parameters, there was no significant effect of the kV value. For BV/TV, ‘90kV’
differed significantly from the other kV settings; for SMI, ‘64kV vs. 73kV’ was significant. For
BS/TV, fractal dimension, connectivity density, branches, junctions and triple points, values
incrementally decreased at larger voxel sizes, whereas an increase was seen for trabecular
thickness, trabecular spacing, SMI and branch length. For anisotropy and plateness, no (or little)
effect of voxel size was seen; for BV/TV, the effect was inconsistent.
Conclusion: Most bone structure parameters are not affected by the kV if the radiation dose is
constant. Parameters dealing with the trabecular structure are heavily affected by the voxel size.
Key words: bone quality; computer-assisted image processing; cone-beam computed tomography;
trabecular bone
59
MAY 20th-21st, 2015
TRI-UNIVERSITY CONSORTIUM
P-30
Observation of Cervical Demineralization Induced by Streptococcus
Mutans Using SS-OCT
Tezuka Hiroki1*, Shimada Yasushi1, Matin Khairul1, Sadr Alireza1, Tagami
Junji1, Sumi Yasunori2
Cariology and Operative Dentistry, Tokyo Medical and Dental University, Japan
Department for Advanced Dental Research Center of Advanced Medicine for Dental and
Oral Diseases National Center for Geriatrics and Gerontology, Japan
1
2
Objective: Exposed root surfaces are subject to biofilm stagnation that can result in caries
formation. Swept-source optical coherence tomography (SS-OCT) is a noninvasive interferometric
imaging method that can create cross-sectional images of tissues. In this study, cervical enamel
and dentin demineralization induced by cariogenic biofilm was evaluated using SS-OCT.
Materials and Methods: An SS-OCT system (Dental OCT System Prototype2, Panasonic Healthcare)
with a center wavelength of 1330 nm was used. Thirty CEJ sections of human extracted teeth were
cut into blocks (5×5×2 mm in size) and divided into 3 groups of 10 specimens each, which were
subjected to demineralization for 1, 2 or 3 weeks. Streptococcus mutans suspension was applied
to form cariogenic biofilm on the surface using oral biofilm reactor (OBR). The specimens were
subjected to biofilm in heart infusion solution at the incubator for each period. After incubation,
the biofilm was removed by NaOH, and enamel and dentin demineralization was observed around
CEJ by SS-OCT and confocal laser scanning microscope (CLSM). The depth of areas with high
brightness values was calculated as demineralization depth using image analysis software (ImageJ,
NIH).
Results: After the incubation of cariogenic biofilm, enamel subsurface around CEJ showed
highlighted zone in SS-OCT. CLSM cross-sectional images confirmed that the bright zone which
increased in depth with incubation time was demineralized tissue. In dentin, the demineralization
depth was found to be deeper than enamel at each stage, indicating more rapid progress of lesion
at the dentin side. At later stage, the thin enamel right at the CEJ appeared to be highly vulnerable
to loss due to both weakening by demineralization and undermined support from dentin.
Conclusion: SS-OCT appears to be a promising modality to detect cariogenic demineralization,
and understand mechanism and progress pattern of lesions at the cervical zone.
Key words: biofilm; CEJ; SS-OCT; Streptococcus mutans
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TRI-UNIVERSITY CONSORTIUM
MAY 20th-21st, 2015
P-31
Correlation Among Pharyngeal Airway Dimension and Position
and Dimension of Surrounding Structures in Growing Thai
Orthodontic Patients with Normodivergent Facial Pattern
Janeta Chavanavesh*, Sirima Petdachai, Vannaporn Chuenchompoonut
Faculty of Dentistry, Chulalongkorn University, Bangkok, Thailand
Objective: To assess sexual dimorphism and correlation among pharyngeal airway dimensions,
bony and soft tissue variables, and skeletal ages.
Materials and Methods: 418 pretreatment lateral cephalometric radiographs (183 males, 235
females) of growing orthodontic patients [6-20 years old; divided into 3 skeletal ages, pre-pubertal
(CS 1,2), pubertal (CS 3,4), and post-pubertal (CS 5,6)], Faculty of Dentistry, Chulalongkorn
University were collected from 2007-2014. 12 angular, 13 linear, and 3 area cephalometric
measurements were analyzed. Sexual dimorphism was assessed by Student’s t-test. Pearson’s and
Spearman’s correlation coefficients were applied to explain variable correlations.
Results: Sexual dimorphism was found only in the post-pubertal period. Nasophayngeal,
oropharyngeal, and total pharyngeal area measurements, and airway width at the level of tongue
base highly and positively correlated with vertical tongue and hyoid position, tongue length, and
skeletal ages. Other airway variables also showed significant correlation to mandibular position,
vertical and horizontal hyoid and tongue position, and tongue thickness. Angular measurements
of tongue and hyoid horizontal position highly correlated with linear measurements. Angular
measurements of tongue and hyoid vertical position showed significantly moderate to high
correlation with linear measurements.
Conclusion: Males had larger airway dimensions than females in post-pubertal period. Skeletal
ages, hyoid position, tongue position and dimension, including mandibular position correlated
with upper pharyngeal airway dimensions. The new angular measurements might be easier and
practical parameters used to measure hyoid and tongue position.
Key words: angular tongue and hyoid measurement; dimension and position of surrounding structures
of pharyngeal airway; growing; normodivergent facial pattern; upper pharyngeal airway
dimension
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MAY 20th-21st, 2015
TRI-UNIVERSITY CONSORTIUM
P-32
Monitoring of Cariogenic Demineralization at Adhesive Interface
Using SS-OCT
Horie Kei1*, Shimada Yasushi1, Matin Khairul1, Sadr Alireza1, Tagami Junji1,
Sumi Yasunori2
Cariology and Operative Dentistry, Tokyo Medical and Dental University, Japan
Department for Advanced Dental Research Center of Advanced Medicine for
Dental and Oral Diseases National Center for Geriatrics and Gerontology, Japan
1
2
Objective: Cariogenic bacteria from dental biofilm can colonize at enamel-composite interface to
cause subsurface secondary caries. Conventional diagnostic methods can only detect late stage
secondary caries under composite restorations. Swept-source optical coherence tomography
(SS-OCT) is a noninvasive diagnostic method for cross-sectional imaging of internal biological
structures. The objective of this study is to evaluate enamel demineralization at composite
restoration caused by cariogenic biofilm using SS-OCT.
Materials and Methods: Round-shaped cavities (2.0 mm diameter × 1.0 mm depth) were prepared
on buccal enamel of extracted human third molar teeth. The cavities were restored with a
flowable resin composite (Estelite Flow Quick) using a two-step self-etch adhesive (SE Bond)
or an all-in-one self-etch adhesive (Tri-S Bond).
Streptococcus mutans suspension was applied to form cariogenic biofilm on the surface using an
oral biofilm reactor (OBR). After 7, 14 and 21 days incubation, the biofilm was removed to
observe enamel and underlying dentin demineralization.
The demineralization depth was calculated according to the pixels with high brightness values at
the interfacial zone using digital image analysis software. The results were statistically compared
among materials and substrates with statistical significance defined as p<0.05.
Results: After the incubation of cariogenic biofilm, formation of demineralized layer around the
restoration was confirmed as intensified backscattering in SS-OCT image. The highlighted zone
tended to increase in depth with the progress of experimental period.
Conclusion: Pre-cavitation demineralization of enamel around composite restorations caused by
cariogenic biofilm was observed as bright zone in SS-OCT. SS-OCT appears to be a promising
modality for the detection of secondary caries in early stage.
Key words: biofilm; secondary caries; SS-OCT, Streptococcus mutans
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