Finals lecture- direct composite & history


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Finals lecture- direct composite & history

  1. 1. Introduction
  2. 2. I. Class 1 DirectComposite Restoration Preparation design: Conventional (class I,II,V) in amalgam/90˚or buttjoint Modified (classV) Bevealed conventional (rarely used)
  3. 3. I. Class 1 Direct Composite Restoration B. Inverted cone with roundedcaries Provide flat floors Produces a more stronger margin on the occlusal cavosurface Creates preparation walls that converge occlusally Occlusally more conservative facial – lingual preparation width
  4. 4. Class II Conventional direct compositeA. Occlusal preparation: 330 or 245 diamond made parallel to the long axis of the tooth. Pulpal depth is 1.5 mm from the central groove (about 0.2mm in dentin); follows the rise and fall of DEJ mesiodistally but relatively flat faciolingually.
  5. 5. Class II Conventional direct compositeB. Proximal Box: Facial, lingual and gingival extensions dictated by extend of caries or old restoration; may not be extended beyond the contact with the adjacent tooth. Walls at 90˚, axial wall to 0.2mm in dentin Gingival floor flat with minimal extension Retained by micromechanical retention, no secondary retention necessary.
  6. 6. III. Class VI Composite RestorationA. Preparation design The typical class VI tooth preparation should be as small in diameter and as shallow in depth as possible.B. Flame - shape or round diamond Either a flame-shaped or round diamond instrument to roughen the prepared surfaces.
  7. 7. Indirect tooth colored RestorationIndications: Esthetic Large defects or previous restorations Economic factorsContraindications: Heavy occlusal forces Inability to maintain a dry field Deep subgingival preparation
  8. 8. Definition of termsIndirect: Inlay - restoration of metal, porcelain/ceramic or composite made to fit a tapered cavity preparation and luted into it by a cementing medium. Onlay (overlay) - an inlay that includes the restoration of all of the cusp of a tooth.
  9. 9. Definition of terms Taper -permits an unobstructed removal of the wax pattern and subsequent seating of the material. The wax pattern should be removed from the tooth without distortion.Taper Intracoronal -divergence from the floor of the preparation outwards.
  10. 10. Definition of terms Extracoronal - converge from the cervical to the occlusal or incisal surface. ●shallow cavities (vertical walls unusually short) Requires minimal taper of 2˚ occlusal divergence to enhance resistance and retention. ●deep cavities (increased gingivo-occlusal height ofvertical walls) As much as 5˚ taper to facilitate: Pattern withdrawal, trail seating and cementing of restoration
  11. 11. Types of restorative materials Laboratory-processed inlays andonlays Ceramic inlays and onlays Machinable ceramics or CAD/CAM Feldspathic porcelain Hot-pressed ceramic
  12. 12. Laboratory-processed inlays and onlays Polymerized under pressure, vacuum, inertgas, intense light, heat, or a combination ofthese devices to optimize physical propertiesof composite resins. More resistant to occlusal wear vs directcomposites but less wear resistance thanceramics. Easily adjusted, low wear of opposing teethgood esthetics and has potential for repair.
  13. 13. Laboratory-processed inlays and onlaysIndications: If maximum resistance is desired from composite restoration. Achievement of proper contour and contacts would be difficult with direct composite. If ceramic restoration is contraindicated because of wear of opposing dentition.
  14. 14. Advantages of heat curedcomposite inlay/onlay restoration Improved physical properties/durability andwear resistance compared to direct compositesystems. Depth of cure not a problem unlike withdirect composite where there is limited depthof cure. Excellent marginal adaptation since the lutingcomposite fills any marginal contraction gappresent. Non-extent polymerization shrinkage exceptin luting resin cement. Post-operative sensitivity seldom
  15. 15. Ceramic inlays and onlays Esthetics, durable, improvedmaterials, fabrication techniques,adhesives and non based lutingagents.
  16. 16. Fabrication steps forceramic inlays and onlays After tooth preparation, an impressionis made and a “master” working cast ispoured of die stone. The die is duplicated and poured with arefractory investment capable ofwithstanding porcelain firingtemperatures. The duplication methodmust result in the master die and therefractory die being accuratelyinterchangable.
  17. 17. Fabrication steps forceramic inlays and onlays Porcelain is added into the preparationarea of the refractory die and fired inan oven. Multiple increments and firingsare necessary to compensate forsintering shrinkage. The ceramic restoration is recoveredfrom the refractory die, cleaned of allinvestment, and seated on the masterdie and working cast for finaladjustments and finishing.
  18. 18. Feldspathic porcelain Partially crystalline minerals (feldspar,silica, alumina) dispersed in a glassmatrix. Porcelain restorations are made fromfinely ground ceramic powders that aremixed with distilled water or a specialliquid, shaped into the desired form,then fired and fused together to form atranslucent material that looks liketooth structure.
  19. 19. Feldspathic porcelain Some ceramic inlays and onlays arefabricated in the dental laboratory byfiring dental porcelains on refractorydies. Advantage: Low start-up cost Disadvantage: its technique sensitivity
  20. 20. Hot Pressed Glass ceramics Glass could be modified with nucleatingagents and on heat treatment, bechanged into ceramics with organizedcrystalline forms. Such “glass ceramics” were stronger,had a higher melting point than noncrystalline glass, and had variablecoefficients of thermal expansion.
  21. 21. Hot Pressed Glass ceramicsAdvantages: Similarity to traditional “wax-up” processes Excellent marginal fit Relatively high strength The surface hardness and occlusal wear ofthese ceramics are similar to those ofenamel. Stronger than porcelain inlays made onrefractory dies, they are still quite fragileuntil cemented.
  22. 22. Hot Pressed Glass ceramicsDisadvantges: its translucency, which necessitatedexternal application of all shading. Not significantly stronger than firedfeldspathic porcelains they do seemto provide better clinical service.
  23. 23. Chronological Events of Restorative MaterialsHistory First recommended over 25 years ago for posterior use.1907 – cast gold1908 – silicate cement First direct tooth colored restorative material. Disadventage: Insoluble to oral fluid
  24. 24. Chronological Events of Restorative Materials1950 – bonding agents1955 – acid etching by Micheal J. Buonocore1960 – sealants1962 – composite resin -direct filled restorative material
  25. 25. Chronological Events of Restorative Materials1962 – composite resin According to the size of the filler: Macrofill – for class V (problem: abfraction) Microfill – anterior restoration Hybrid Microhybrid composite Nanofilled composite
  26. 26. Chronological Events of Restorative Materials1962 – composite resin Two types of composite: 1. Packable composite alternative to amalgam Supplied: unit dose, compules or in syringe Higher filler loading Fibers Porous filler particles Irregular filler particles Viscosity modifiers
  27. 27. Chronological Events of Restorative Materials1962 – composite resin Advantages: Produce acceptable class II restoration High depth of cure possible Bulk fill technique Filler loading: 80% Medium to high strength High stiffness Low wear rate: 3.5um/year Molecules of elasticity :similar to amalgam
  28. 28. Chronological Events of Restorative Materials1962 – composite resin Disadvantages: New technique Less polishable Limited shades Increased post-operative sensitivity Increased sensitivity to ambient light
  29. 29. Chronological Events of Restorative Materials1962 – composite resin Recommended uses: Class I restoration Class II restoration
  30. 30. Chronological Events of Restorative Materials1962 – composite resin 2. Flowable composites Low viscosity composites Low filler content Ideal for cervical lesion Ideal for non stress bearing area Ideal for first increment in Class I composite
  31. 31. Chronological Events of Restorative Materials1962 – composite resin Advantages: Syringeable Dispensed directly into cavity Adequate strength Disadvantages: Higher polymerization shrinkage Greater potential for microleakage Low wear resistance
  32. 32. Chronological Events of Restorative Materials1968 – Glass ionomer cement Different types: Luting or cementing medium Liner or base Restorative material
  33. 33. Chronological Events of Restorative Materials 1970 – microfill “polishable”composite 1973 – ultraviolet light 1977 – microfill composite Advantages: polishability, wear and resistance and color stability Disadvantages: low flexural/tensil strength, localized wear and thus limited uses posteriorly.
  34. 34. Chronological Events of Restorative Materials 1978 – visible light curingcomposite Mid 1980’s hybrid: Hybrid – 0.04-3um particle size range Examples: brands of hybrid Herculite Prisma APH P-30
  35. 35. Chronological Events of Restorative MaterialsMid 1980’s hybrid Intended for universal useDisadvantage of hybrid: Generalized wear
  36. 36. Chronological Events of Restorative MaterialsMid 1980’s microhybrid: Microhybrid – 0.6-0.7um particle size range Examples: brands of microhybrid Prisma TPH Herculite XRV Charisma Tetric ceram
  37. 37. Chronological Events of Restorative MaterialsMid 1980’s microhybrid: Advantages: Excellent physical properties Good finishing and polishing characteristics Relatively non sticky materials Disadvantage: Do not hold a high polish over time
  38. 38. Chronological Events of Restorative Materials1985 – CEREC ceramic system 1991 – CEREC 1 as modified by siemens 1994 – CEREC 2 with an upgrade dimensional camera 2000 – CEREC 3 with split acquisition/design
  39. 39. CERECChairside Economical Restoration of Esthetic Ceramiics
  40. 40. Chronological Events of Restorative Materials1986 – Heliomolar The sole exception to the microfill group of resins that were introduced for posterior use. 70% filled anterior/posterior microfill resin. very good wear characteristic Less than perfect esthetics
  41. 41. Thank you!