Restorative Composite Resins Col Kraig S. Vandewalle USAF Dental Evaluation & Consultation Service Official Disclaimer • The opinions expressed in this presentation are those of the author and do not necessarily reflect the official position of the US Air Force or the Department of Defense (DOD) • Devices or materials appearing in this presentation are used as examples of currently available products/technologies and do not imply an endorsement by the author and/or the USAF/DOD Overview • Direct restoratives – composition – classification – performance factors • Flowable • Packables Click here for briefing on composite resins (PDF) Composite • Material with two or more distinct substances – metals, ceramics or polymers • Dental resin composite – soft organic-resin matrix • polymer – hard, inorganic-filler particles • ceramic • Most frequently used – esthetic-restorative material Leinfelder 1993 History • 1871 – silicates – alumina-silica glass & phosphoric acid – very soluble – poor mechanical properties • 1948 - acrylic resins – polymethylmethacrylate – high polymerization shrinkage Rueggeberg J Prosthet Dent 2002 History (cont.) • 1962 – Bis-GMA – stronger resin • 1969 – filled composite resin – improved mechanical properties – less shrinkage – paste/paste system • • • • 1970’s – acid etching and microfills 1980’s – light curing and hybrids 1990’s – flowables and packables 2000’s – nanofills Rueggeberg J Prosthet Dent 2002 Indications • Anterior restorations • Posterior restorations – preventive resin – conservative class 1 or 2 Contraindications • Large posterior restorations • Bruxism • Poor isolation Advantages • • • • • Esthetics Conservation of tooth structure Adhesion to tooth structure Low thermal conductivity Alternative to amalgam Disadvantages • Technique sensitivity • Polymerization shrinkage – marginal leakage – secondary caries – postoperative sensitivity • Decreased wear resistance Composition • Resin matrix – – – – monomer initiator inhibitors pigments Bis-GMA CH3 O CH2=C-C-O-CH2CH-CH2O CH3 OH -CCH3 O OCH2CHCH2O-C-C=CH2 OH CH3 • Inorganic filler – glass – quartz – colloidal silica • Coupling Agent Phillip’s Science of Dental Materials 2003 Monomers • Binds filler particles together • Provides “workability” • Typical monomers – Bisphenol A glycidyl methacrylate (Bis-GMA) O CH2=C-C-O-CH2CH-CH2O CH3 OH CH3 -C- O OCH2CHCH2O-C-C=CH2 CH3 OH CH3 – Urethane dimethacrylate (UEDMA) CH3 CH3 O O O O CH2=C-C-O-CH2CH2-O-C-NHCH2CH2CHCH2-C-CH2-NH-C- OCH2CH2O-C-C=CH2 CH3 CH3 CH3 – Triethylene glycol dimethacrylate (TEGMA) O O CH2=C-C-O-CH2CH2-OCH2CH2 OCH2CH2O-C-C=CH2 CH3 CH3 Monomers • Bis-GMA – extremely viscous • large benzene rings – lowered by adding TEGDMA • • • • freely movable increases polymer conversion increases crosslinking increases shrinkage O CH3 CH2=C-C-O-CH2CH-CH2O CH3 OH -CCH3 O OCH2CHCH2O-C-C=CH2 OH CH3 Monomers • Shrinkage –2–7% – marginal gap formation Filler Particles • Crystalline quartz – larger particles – not polishable • Silica glass – – – – barium strontium lithium pyrolytic • sub-micron Phillip’s Science of Dental Materials 2003 Filler Particles • Increase fillers, increase mechanical properties strength abrasion resistance esthetics handling • 50 to 86 % by weight • 35 to 71% by volume Fracture Toughness – – – – % Filler Volume 2 1.5 1 0.5 0 0 28 37 48 53 62 Ferracane J Dent Res 1995 Coupling Agent • Chemical bond – filler particle - resin matrix • transfers stresses • Organosilane (bifunctional molecule) – siloxane end bonds to hydroxyl groups on filler – methacrylate end polymerizes with resin CH2 Bis-GMA OH CH3-C-C-O-CH2-CH2-CH2-Si-OH Bonds with resin O Silane OH Bonds with filler Phillip’s Science of Dental Materials 2003 Inhibitors • Prevents spontaneous polymer formation – heat – light • Extends shelf life • Butylated Hydroxytoluene Phillip’s Science of Dental Materials 2003 Pigments and UV Absorbers • Pigments – metal oxides • provide shading and opacity • titanium and aluminum oxides • UV absorbers – prevent discoloration – acts like a “sunscreen” • Benzophenone Phillip’s Science of Dental Materials 2003 Visible-Light Activation • Camphorquinone – most common photoinitiator • absorbs blue light – 400 - 500 nm range • Initiator reacts with amine activator • Forms free radicals • Initiates addition polymerization O CH2=C-C-O-CH2CH-CH2O CH3 OH CH3 -C- O OCH2CHCH2O-C-C=CH2 CH3 Bis-GMA OH CH3 Polymerization • Initiation – production of reactive free radicals • typically with light for restorative materials • Propagation – hundreds of monomer units – polymer network – 50 – 60% degree of conversion • Termination Craig Restorative Dental Materials 2002 C=C C=C C=C C=C C=C C=C C=C C=C C=C C=C C=C C=C C=C C=C C=C polymerization C=C C=C C=C C=C C=C C=C C=C C=C C=C C=C C=C C=C C=C C=C C=C Ferracane Classification System • Historical • Chronological • Based on particle size – traditional – microfilled – small particle – hybrid Phillip’s Science of Dental Materials 2003 Traditional (Macrofilled) • Developed in the 1970s • Crystalline quartz – produced by grinding or milling – large - 8 to 12 microns • Difficult to polish – large particles prone to pluck • • • • Poor wear resistance Fracture resistant Examples: Adaptic, Concise Suitable for Class 3, 4 and 5 Phillip’s Science of Dental Materials 2003 Microfills • Better esthetics and polishability • Tiny particles – 0.04 micron colloidal silica – increases viscosity • To increase filler loading – filler added to resin – heat cured – ground to large particles – remixed with more resin and filler Ground polymer with colloidal silica (50 u) Polymer matrix with colloidal silica Phillip’s Science of Dental Materials 2003 Microfills • Lower filler content – inferior properties • increased fracture potential • lacks coupling agent • lacks radiopacity • Linear clinical wear pattern • Suitable for Class 3, 5 – exceptions with reinforced microfills • Class 1 or 2 Click here for table of microfills Small Particle • 1 - 5 micron heavy-metal glasses • Fracture resistant • Polishable to semi-gloss • Suitable for Class 1 to 5 • Example: Prisma-Fil Silane-coated silica or glass (1-5 u) Polymer matrix Phillip’s Science of Dental Materials 2003 Hybrids • Popular as “all-purpose” – AKA universal hybrid, microhybrids, microfilled hybrids • 0.6 to 1 micron average particle size – distribution of particle sizes Silane-coated silica or glass • maximizes filler loading – microfills added • improve handling • reduce stickiness Polymer matrix with colloidal silica Phillip’s Science of Dental Materials 2003 Hybrids • Strong • Good esthetics – polishable • Suitable – Class 1 to 5 • Multiple available Click here for table of hybrids Table of Properties Property Traditional Microfilled Small Particle Hybrid Compressive strength (MPa) 250-300 250-300 350-400 300-350 Tensile strength (MPa) 50-65 30-50 75-90 70-90 Elastic Modulus (GPa) 8-15 3-6 15-20 7-12 Coefficient of Thermal Expansion (10-6/ºC) 25-35 50-60 19-26 30-40 Knoop Hardness 55 5-30 50-60 50-60 Phillip’s Science of Dental Materials 2003 Newer Classification System • Based on particle size – megafill • 0.5 - 2 millimeters – macrofill • 10 - 100 microns – midifill • 1 - 10 microns • Most new systems – minifillers • Newest trend – nanofillers – trimodal loading • prepolymerized – minifill • 0.1 - 1 microns – microfill • 0.01 - 0.1 microns – nanofill • 0.005-0.01 microns Bayne JADA 1994 Midi -filler 2 um (beachball) Mini -filler 0.6 um (canteloupe) Microfiller .04 um (marble) Nanofiller .02 um (pea) Relative Particle Sizes (not to scale) Nanofill vs. Nanohybrid • Nanofills – nanometer-sized particles throughout matrix • Nanohybrids – nanometer-sized particles combined with more conventional filler technology Swift J Esthet Restor Dent 2005 Nanofilled Composite • Filtek Supreme (3M ESPE) • Filler particles – filled: 78% wgt – nanomers • 0.02 – 0.07 microns – nanocluster • act as single unit – 0.6 – 1.4 microns Click here for technical profile Click here for DECS evaluation Performance Factors • Material factors – biocompatibility – polymerization shrinkage – wear resistance – polish mechanisms – placement types – mechanical & physical properties Biocompatibility • Tolerated by pulp – with good seal • Rare allergic reactions – HEMA • Cytotoxicity – short lived • not a chronic source • Degree of cure important – decrease free monomer Phillip’s Science of Dental Materials 2003 Systemic • Estrogenic effects seen in cell cultures – impurities in Bis-GMA-based resins • Bis-phenol A in sealants – Olea EHP 1996 » click here for abstract – however, insignificant short-term risk • literature review – Soderholm JADA 1999 » click here for abstract Polymerization Shrinkage • Significant role in restoration failure – gap formation • secondary caries formation • marginal leakage • post-operative sensitivity • Counteract – lower shrinkage composites – incremental placement Composite Wear • Less wear – small particle size • less abrasion – heavier filled • less attrition – non-contact areas • 3 - 5 times less – less surface area – anterior location • premolars vs. molars Hilton Oper Dentistry: A Contemporary Approach 2001 Composite Wear • Reduced wear with smaller particles – less plucking leaving voids • Higher filler loads for enhanced properties – correlations between wear and fracture toughness and flexure strength • Higher cure of resin matrix to resist scratching and gouging by abrasives Hilton Oper Dentistry: A Contemporary Approach 2001 Polish Mechanisms • Acquired polish – clinician induced • Inherent polish – ultimate surface • Microfills – high acquired, high inherent • similar resin matrix and fillers wear more evenly • Hybrids – high acquired, acceptable inherent Adept Report 1992 Polish Mechanisms Small Particle Hybrid Microfilled Composite Acquired Polish Time Linear wear pattern Inherent Polish Adept Report 1992 Shaded vs. Anatomic Placement • Shaded – shade selected from middle third of tooth – shade guide gives recipe for multiple shades • Anatomic – highly chromatic dentin matched to existing dentin – colorless enamel replaces existing enamel Click here for details Shaded Anatomic Dentists Ceramists “Create Shade” “Match Shade” Trans Enamel Trans Enamel A1 Enamel A1 Dentin Enamel Value A3/A4 Dentin Enamel Value Placement Types Composite Brands • Shaded – – – – – – – 4 Seasons (Ivoclar Vivadent) Esthet-X (Dentsply) Filtek Supreme (3M ESPE) Point 4 (Kerr) Venus (Heraeus Kulzer) Renamel (Cosmedent) Gradia Direct (GC) • Anatomic – 4 Seasons (Ivoclar Vivadent) – Vitalescence (Ultradent) – Miris (Coltene/Whaledent) Jackson PPAD 2003 Composite Selection • Anterior/stress (Class 4) – hybrid • mini- or midi-fill – hybrid/microfill veneer combo • Anterior/non-stress (Class 3 or 5) – hybrid • mini-fill – microfill Composite Selection • Posterior – hybrid • mini- or midi-fill – reinforced microfill Selecting a Brand • Contents of kit – shades – bonding agent – unit-dose compules vs syringes • Indications – anterior, posterior, both? • Cost of kit – refills Click here for synopsis of restorative composite resins Government Price ($/gm of refill resin) 8.49 8.53 8.79 8.9 9 9.44 11.37 9.95 10.15 10.21 7.58 6.5 4 Se as G ra ons di a Po G st ra di H a er cu A n t lit e XR Pr V od ig y Po in t4 Z1 00 Vi Ven ta us le sc en c Es e th et X Z2 50 Pr em i Su se pr em e 6.3 Prices current as of Jan 05 Selecting a Brand • Results of lab and clinical studies • Compositional characteristics – % filler content – average filler particle size Click here for synopsis of restorative composite resins Radiopacity (mm of aluminum) 3 2 ISO Requirement 1 De nt in Gr ad ia An t Ve nu s Su pr em e 4 Se as on s En am Vi el ta les ce nc Gr e ad ia Po st 0 Source: USAF DECS Project 03-024 Surface Hardness (24 hrs) Source: USAF DECS Project 03-37 40 30 20 10 Po in t4 4 Se as on s Pr em is G e ra di a Po st G ra di a An t Ve nu s Es th et -X 0 Z2 50 Su pr em Vi ta e le sc en ce KHN Horizontal lines connect nonsignificant differences (p<0.05); N=5 Flexural Strength (24 hrs) Source: USAF DECS Project 03-037 160 140 120 100 80 60 40 20 0 Supreme 4 Seasons Venus Gradia Ant Premise Horizontal lines connect nonsignificant differences (p<0.05); N=5 Gradia Post Volumetric Shrinkage Source: USAF DECS Project 03-037 5 4 3 2 1 ow Fl et -X R en ew s Ve nu Z1 00 Pr em is e 4 Se as on s Es th G ra di a D ire ct 0 A 11 0 % Horizontal lines connect nonsignificant differences (p<0.05); N=5 Composite Variants • Packable • Flowable Packable Composites • Marketed for posterior use – increase in viscosity • better proximal contacts? • handle like amalgam? • Subtle alteration of filler – shape – size – particle distribution • Similar resin chemistry and filler volume Click here for table of packable composites Packable Composites • Mechanical properties – similar to hybrids 1.8 1.6 Fracture Toughness 1.4 1.2 1 0.8 0.6 ALERT Solitare SureFil Heliomolar Z100 0.4 0.2 0 Choi J Esthet Dent 2000 Click here for abstract Proximal Contact Studies • Packables similar to hybrids – diameter and tightness • Best contacts – sectional matrix system Peumans Dent Mater 2001 -click here for abstract Klein Am J Dent 2002 Packable Composite Resin Depth of Cure 100 % Hardness Ratio 80 96.9 96.2 91.2 85.1 71.5 70.2 70.3 2 mm 5 mm 55.4 60 41.4 40 22.4 20 0 0 Pyr-D Prodigy SureFil Alert Solitaire 0 Pyr-E Choi J Esthet Dent 2000 Click here for abstract Packable Vs. Hybrid Composites • • • • • Mechanical properties similar Wear properties similar Curing depths similar Similar proximal contacts Drier, denser feel Click here for more details Choi J Esthet Dent 2000 Peumans Dent Mater 2001 Flowable Composites • Marketed • Particle size similar to hybrid composites • Reduced filler content – Weight Percent – class 1, 3, 5 – liner Percent Filler Loading 80 70 60 50 40 30 20 10 0 Aeliteflo FloRestore Revolution Ultraseal+ Prodigy reduces viscosity Bayne JADA 1998 Click here for abstract Liners Under Direct Composites • Increased flow • Increased shrinkage • Improved marginal integrity? – laboratory studies equivocal • most studies show no benefit – Braga JADA 2003 » click here for abstract • Reduced post-operative sensitivity? – no clinical evidence of reduction – Perdigao Quint Int 2004 » click here for abstract Polymerization Shrinkage % 5 4 3 2 1 0 o Fl Ae e t li lu o v e R n it o W e av ow l F -it ri t Te c ow l F rt e Al i F re u S l 00 1 Z li e H ar l o m o Tolidis JDR 1999 Radiopacity • Reduced radiopacity? – product specific – may be more difficult to distinguish on radiograph Gray value 250 200 150 100 Tetric Flow Flow-it Enamel Revolution FloRestore UltraSeal+ 50 0 Murchison Quint Int 1999 Click here for abstract Flowable Composite • Mechanical properties – inferior to hybrids Fracture Toughness Flexure Strength Prodigy Ultraseal + Revolution FloRestore Aeliteflo 0 0.5 1 1.5 MPa 2 2.5 0 50 100 150 200 MPa Bayne JADA 1998 Click here for abstract Flowable Composites • Clinical applications – preventive resin restorations – small Class 5 – provisional repair – composite repair – liners?? Regular Material Usage* • • • • • • • • • Civilian Practitioners Flowable Composite 81% Hybrid Composite 69% Amalgam 67% All-Purpose Composite 53% Microfill Composite 52% Resin-modified Glass ionomer 45% Packable Composite 33% Compomer 7% Other 1% *Multiple responses DPR 2005 Review of Clinical Studies (Failure Rates in Posterior Permanent Teeth) % Annual Failure 8 6 4 2 0 Amalgam Direct Comp Comp Inlays Longitudinal Ceramic CAD/CAM Inlays Inlays Gold Inlays & Onlays GI Cross-Sectional Hickel J Adhes Dent 2001 Review of Clinical Studies (Failure Rates in Posterior Permanent Teeth) % Annual Failure 15 Standard Deviation 10 Longitudinal and Cross-Sectional Data 5 AR T el Tu nn I G Di re Am al ga m ct Co m Co p m po m Co er m p In Ce la ra ys m ic In la ys CA D/ CA M Ca st G ol d 0 Manhart Oper Dent 2004 Click here for abstract Purchasing Considerations Federal Service • Universal hybrid systems are suitable for both anterior and posterior restorations – may not need to stock packable systems • • • • additional expense to maintain no improvement in mechanical properties no improvement in proximal-contact formation no increase in depth of cure Click here for more details Purchasing Considerations Federal Service • Most cases often only need one shade type • Complex cases may need multiple shades applied in layers – larger Class 4, direct veneers, diastema closures • Wide diversity of kits available – simple kits with only a few shades – complete kits with multiple shades in various opacities; bonding agents, dispenser guns, shade guides Click here for synopsis of restorative composite resins Purchasing Considerations Federal Service • Simple universal hybrid kit in compact case for routine individual use in operatories or suites – many systems available • e.g., Prodigy (Kerr) • More complete universal hybrid kit for general use by entire facility or training program – several systems available • e.g., 4 Seasons (Ivoclar Vivadent) Click here for synopsis of restorative composite resins Future Composites • Low-shrinking monomers – expanding spiroorthocarbonates – epoxy-based resins – liquid crystal • Self-adhesive? Click here for details Acknowledgments • Dr. Dave Charlton • Dr. Jack Ferracane • Dr. Tom Hilton Questions/Comments Col Kraig Vandewalle – DSN 792-7670 – [email protected]
© Copyright 2024