FLOWABLE COMPOSITE

FLOWABLE COMPOSITE

اسلاید 1: FLOWABLE COMPOSITERobert W. Hasel D.D.S.Associate ProfessorRestorative DentistryMidwestern UniversityCollege of Dental MedicineGlendale, Arizona

اسلاید 2: Composite HistoryDr. R.L. Bowen‘bis-GMA’1956“Adaptic”1960’sLight-initiated composite1970’sMicrofilled composite1990’sHybrid compositeFlowable, packable, etc.2000’sNanocompositeNon-shrink composite ?Posterior composite1980’s

اسلاید 3: Development of MaterialsUSACOMPOSITESUKGLASS-IONOMERSBRITISH DEVELOPMENTVISIBLE LIGHT CURINGAMERICAN DEVELOPMENTRESIN-MODIFIEDGLASS-IONOMERS

اسلاید 4: Resin Composites & derived materialsDevelopmentDissatisfaction with silicates/acrylicsDevelopment of ‘Bowen’s resin’ – Bis-GMAIntroduction of first materials – two paste systemsDevelopments in filler contentSmaller particlesMicrofine particlesCommand setting – UV cureSingle paste – VLCChange in viscosity – flowable/packableNanocomposites? Low shrinkage materials?

اسلاید 5: TECHNOLOGY

اسلاید 6: Alter the Paradigm

اسلاید 7: Resin matrixCeramic fillersSilane coupling agentDental compositeReview

اسلاید 8: Note : vol % is 15-20 % lowerFillers TypeSiO2 , barium glass, ZrO2 Sizemacrofills (>10 mm); midifills (1-10 mm) minifills (0.1-1 mm); microfills (0.04-0.1 mm); nanofills (0.02-0.07 mm) Content40% - 80+% by weightVariations

اسلاید 9: Classification Traditional (‘macrofilled’) Glass particles ; size 1-15 mm Microfilled Amorphous silica ; size ~ 0.04 mm HybridFiller load ~ 80 wt% Glass particles (Avg size ~ 5 mm) + microfillersBased on filler sizeLutz & Philips, 1983

اسلاید 10: Zirconia/silica sol-gel process spherical polishability continuum in sizes high packing density (85 wt %)Z100, Z250, Palfique (3M ESPE) (Tokuyama)Fillers

اسلاید 11: Resin matrixMonomer : bis-GMA Diluent : TEGDMAPhotoinitiator : camphorquinoneCo-initiator : tertiary amine(light-activated composite)Review, bis-EMA, UDMADimethacrylate

اسلاید 12: CQActivated stateFreeradicalAmine co-initiator+C=CC=CC=CDimethacrylate monomerC=CC=CC=CC=CC=CC=CC=CC=CC=CC=CC=CC=CC=CO2Reaction

اسلاید 13: Polymerization shrinkageCurrent systems : 2-3 % vol shrinkage Methacrylate-based monomers Free radical, addition polymerizationProducts in development : ‘no shrinkage’ Ring-opening reactionexpandResin matrix

اسلاید 14: O2 inhibition layer= uncured monomer film at the surface film thickness ~ 10 mm not biocompatible should be removed ? between increments ?‘Most monomers have some biologic activity ………but … biocompatible when reacted into polymer…’BiocompatibilityResin matrix

اسلاید 15: Well cured Remove O2 inhibition layer Avoid contact with uncured resin 5% of dental personel have contact allergy to methacrylates Protective gloves are inadequate Wallenhammar et al, 2000 Estrogenic effect Olea et al, 1996 Adverse reaction: asthma, blister, rashes Hallstrom, 1993 Oral lichenoid lesions Lind, 1998RecommendationsResin matrix

اسلاید 16: FLOWABLE COMPOSITE

اسلاید 17: Problems with Paste CompositeDifficult to useDifficult to manipulateSticky, pull back VoidsPorositiesUnpolymerized areasShrinkageSurface and Marginal integrity

اسلاید 18: Problems with Paste CompositeDifficult to useDifficult to manipulateSticky, pull back VoidsPorositiesUnpolymerized areasShrinkageSurface and Marginal integrityEasyEasyStays putEliminatesEliminatesLessMinimizes (technique)Best

اسلاید 19: RheologyDefinitionRheology is the study of theflow and deformation of matterDental importanceImportant for any material placed in the mouth in a fluid state – examples:Impression materialsDirectly-placed tooth restorative materials

اسلاید 20: Rheology of Resin CompositesSEALANTSMICROFILLFLOWABLEHYBRID &RELATED MATERIALSPACKABLE orCONDENSABLEVERY WIDE RANGE OF MATERIALSINCREASING VISCOSITY

اسلاید 21: ViscosityBACA has highestviscosityC is the mostfluidB is inter-mediate

اسلاید 22: dkjdfjklHIGH FLUIDITYLOW VISCOSITYLOWFLUIDITYHIGHVISCOSITY

اسلاید 23: Rheology of Resin CompositesGeneral idea - lower filler content - usually hybrid filler. Includes fumed silica, claimed to give thixotropy*Original claims (patent literature) - recommended for Class I, II, III, IV and V cavitiesNow being recommended for many applications (e.g. fissure sealing – discussed later)*What is thixotropy?

اسلاید 24: Rheology of Resin CompositesThixotropy is a reversible structural breakdown of a material that occurs when the material is stressedFlowable composites were designed to be thixotropicThis means that when the material is being syringed, the high stress from syringing breaks down some of the structure (e.g. hydrogen bonding), so the material flowsBut when the material is placed into the cavity, it will not flow (‘non-drip’) because the hydrogen bonding structure quickly recovers

اسلاید 25: Flowable CompositesTHERE ARE SIGNIFICANT ‘FLOW’ PROPERTYDIFFERENCES BETWEEN DIFFERENT PRODUCTSVERY FLUID;VIRTUALLY NEWTONIAN:NO “THIXOTROPY”-- contrast with ....

اسلاید 26: Flowable CompositesTHERE ARE SIGNIFICANT ‘FLOW’ PROPERTYDIFFERENCES BETWEEN DIFFERENT PRODUCTS…contrastHIGHER VISCOSITY;SHOWS “SHEAR THINNING”DIFFERENT TECHNIQUE AND APPLICATIONS?

اسلاید 27: Flowable CompositesTHERE ARE SIGNIFANT COMPOSITIONALDIFFERENCES BETWEEN DIFFERENT PRODUCTS

اسلاید 28: Flowable CompositesSOME MATERIALS (at least 34!) – examples - Florestore (Den-Mat)Flowable composite (Henry Schein)Revolution – Formula 2 (Kerr)Starflow (Danville Materials)

اسلاید 29: Flowable CompositesThere is no such thing as a standard flowable material34 brands (some identical); many with different formulations, handling characteristics, properties and applicationsConfusion because of untested materials - no track record of clinical success

اسلاید 30: 1. Philosophy1. Dental materials do not naturally belong in the mouth!2. All synthetic materials evoke a host response3. Synthetic materials not as good as health tooth substance4. Best treatment is the least treatment5. Best treatment is the most durable treatmentTHEREFORE – there is an obligation to prevent dental disease, and where treatment is necessary, to choose the best materials, and manipulate them in such a way that optimum properties are obtained.

اسلاید 31: Principles of Selection(i) Evidence from laboratory data(ii) Clinical performance(iii) Esthetic considerations(iv) Clinical needs(v) Patient’s preferences(vi) Operator’s preferences(vii) Cost effectiveness(viii) Environmental considerations

اسلاید 32: higher shrinkage compromised mechanical propertiesFiller content (wt %)5668537580flowablehybridWear (mm)2828262122flowablehybridFracture toughness1.361.242.051.90flowablehybridFlowable compositesFiller contents haveCaught up

اسلاید 33: Conclusion The criteria for choice of a material include not only factors such as physical and mechanical properties, but also include ease of manipulation. Note that there are no standard specifications for these materials, and that they differ considerably in their flow properties.

اسلاید 34: BICM E PBiocompatibilityInterfacial propertiesChemical propertiesMechanical & physical propertiesEsthetic considerationcured vs uncuredadhesive system esteraseOOC-C=CBiodegradation& PolishabilityFlowable / PackablePractical questionsNeed improvements?

اسلاید 35: Failure ZoneBiofilmImproper EtchingThick LayersUnpolymerized areasPorositiesVoids in the bodyMarginal IntegritySurface IntegrityShrinkage

اسلاید 36: FAILURE ZONEBiofilmImproper EtchingImproper CuringThick LayersUnpolymerized areasPorositiesVoids in the bodyMarginal IntegritySurface IntegrityShrinkage