DHE132 LECTURE 3 quiz#2

  1. Direct Placement =
    directly into the cavity preparation
  2. Common materials for direct placement:
    • Composite resin
    • Glass ionomer cement
    • Resin-modified glass ionomer cement-Hybrid ionomer
    • Compomer
  3. Restorative Classification for Class I:
    • Lingual/Occlusal
    • Image Upload 1
  4. Restorative Classification for Class II:
    • Posterior interproximal
    • Image Upload 2
  5. Restorative Classification for Class III:
    • Anterior interproximal 
    • Image Upload 3
  6. Restorative Classification for Class IV:
    • Anterior Incisal edge
    • Image Upload 4
  7. Restorative Classification for Class V:
    • Cervical/gum line
    • Image Upload 5
  8. CuspRestorative Classification for Class VI:
    • Cusp
    • Image Upload 6
  9. Composite Material Properties:
    • Restorative material is tooth colored: may be in various shades or one universal shade.
    • Some build-up materials come in colors like blue or gray.
    • Material is usually a putty like consistency
    • can be flowable
  10. Composite Benefits:
    • Esthetics……looks great!
    • Acid etching and bonding agents improve retention
    • Less tooth structure is removed when making cavity preparation than with amalgam…..sometimes small enough to not need anesthetic
    • More thermal insulation than with amalgam
    • Less microleakage due to bonding
    • No mercury
  11. Direct:
    material packed (condensed) directly into a prepared cavity while in a plastic or putty-like consistency.
  12. Esthetic:
    tooth colored to match, pleasing to the eye.
  13. Restoration:
    Returning the tooth to original condition and function.
  14. FIVE Direct Esthetic Restorative Materials:
    • 1.Unfilled Acrylic Resins
    • 2.Composite Resins  Most commonly used
    • 3.Silicate (Porcelain)
    • 4.Glass Ionomers
    • 5.Compomers  (hybrid of two dental materials: dental composites and glass ionomer cement and Fl2)
  15. How should composites be stored:
    • need to be stored away from heat and away from light
    • the refrigerator is best.
  16. What does “Filled” composites mean?
    • “Filled” = Macrofilled / Microfilled / Nanocomposites
    • Improvements: Filler particle size has decreased
    • # of filler particles has increased
    • Therefore shrinkage upon polymerization has decreased
  17. What does “Unfilled” composites mean?
    • “Unfilled” = PF Sealants
    • Flowable
    • Low-viscosity
    • Lightly filled
    • ** materials that are lightly filled shrink more when polymerized, wear more readily, and are weaker
  18. Classification of Composites by Filler Size
    Macrofilled composites:
    • are the first generation of composite resin material.
    • They are conventional composites containing the largest of the filler particles.
    • Provide greater strength but have a duller, rougher surface, and they absorb stains more easily.
    • Image Upload 7
  19. Classification of Composites by Filler Size
    Microfilled composites:
    • were developed to overcome the problems that arose with the larger particle size.
    • They contain much smaller particles, which makes them weaker; however, they polish to a glossy finish and do not absorb stain as easily. Image Upload 8
  20. Classification of Composites by Filler Size
    Hybrid composites:
    • contain both large fillers and microfine fillers.
    • They can be easily polished, have greater strength than the microfilled composites, and have a high wear resistance.
    • Microhybrids use even smaller particles and contain a combination of small particles and microfine particles.
    • Image Upload 9
    • Nanohybrids are microhybrids with nanosized particles added. The ability to add increased numbers of filler particles reduces the amount of resin, and they shrink less when polymerized.

    Universal composites
  21. Classification of Composites by Filler Size
    • have filler particles that are about a thousand times smaller than conventional fillers.
    • They have excellent polishability, wear resistance, and maintain their luster long-term.  Image Upload 10
  22. How big is 1 micron?
    Image Upload 11
  23. Unfilled Acrylic Resins:
    • Not used any more for restorations
    • Expansion and Contraction = Recurrent decay
    • Powder is called polymer
    • Liquid is monomer
    • Polymerization or Curing
  24. Composite Resins:
    • *most commonly used*
    • Bulk-Fill [mixture of two or more materials]
    • Available in two consistencies:Flowable and Viscous nanohybrids
    • Joined together by a silane coupling agent
    • Do NOT use liners/base with eugenol
  25. Eugenol:
    oil extracted from cloves. (Most people associate smell with a dental office).
  26. Composite Resins uses:
    • Restorative material for class III, IV, and V restorations (anterior fillings)
    • Restorations in class I and II cavities (posterior)
    • ‘Direct veneers’ (not as long lasting as indirect porcelain veneers)
  27. Composite Resins  (Packable):
    • Highly viscous microhybrids
    • High volume of filler particles
    • Posterior teeth restoration
    • The high volume of filler particles gives this material a stiff consistency.
    • ▪Packable = no longer popular but are still available on the market.
  28. Core Buildup Composite Resins:
    • replace missing tooth structure
    • bonded to tooth structure
    • minimize bacterial leakage
    • increase retention
    • Heavily filled composites
    • Can be:Light-cured, Self-cured,Dual-cured
    • Cementation
  29. Physical Properties of Composites:
    • Biocompatibility
    • Strength
    • Wear
    • Polymerization shrinkage
    • Degree of conversion
    • Thermal conductivity
    • Coefficient of thermal expansion (CTE)
    • Elastic modulus
    • Water sorption
    • Radiopacity
  30. Strength:
    Most of the composites used today are similar in compressive strength
  31. Wear:
    Composites wear faster than amalgams
  32. Polymerization shrinkage:
    matrix, when cured, usually shrinks away from the cavity walls. Curing in small increments (1 to 2 mm) decreases shrinkage
  33. Thermal conductivity:
    close to natural tooth structure
  34. CTE:
    is greater=undergo a greater change resulting in debonding and leakage
  35. Water sorption:
    The greater the resin content, the more water is absorbed. Water softens the resin matrix, which gradually degrades the material.
  36. Elastic modulus (Young’s modulus):
    The greater the volume of the filler, the stiffer (higher elastic modulus) and more wear resistant the restoration.
  37. Radiopacity:
    Metals such as lithium, barium, or strontium are added to the filler to make the restoration more opaque
  38. Shade Guides:
    • Color tabs used in shade selection
    • Natural light source
    • Drying out of teeth (desiccation)
    • Mixing shades
    • Shades should be selected while the teeth are wet
  39. Components of Composite Resins:
    • Mixture of two or more materials
    • Tooth-colored restorative materials
    • Composition:
    •    Organic resin matrix
    •    Inorganic filler particles:▪glass, quartz, silica, and ceramic
    •    Silane coupling agent = adheres the particles to the matrix
    •    Initiators and accelerators =cause the material to set
    •    Pigments
    • Resins are thick liquids made up of two or more types of organic molecules called oligomers
    • Filler particles added to:
    •    produce strength
    •    reduce shrinkage
  40. Organic Resin Matrix?
    • bis-GMA (bisphenol-A-glycidyl dimethacrylate) *most common
    • UDMA (Urethane Dimethacrylate)
  41. Silane  the Bonding Agent:
    • Reacts with the inorganic filler and organic matrix to:
    •    Allow the two to adhere to each other=Good adhesion
    •    Has low viscosity (flows easily) and can wet the etched tooth
    • Purpose is to improve retention
    • Self-cured or Light-cured
    • Surface is tacky, don’t wipe it off
    • Supplied with the composite kit
    • Applied AFTER acid etching
  42. Factors affecting Light-Curing?
    • Short curing times
    • Inadequate light output
    • Wrong wavelength of light
    • Incorrectly positioned light guide

    Light-cured composite resins must receive the correct amount of radiant energy at the right exposure time and the right wavelength in order for them to polymerize correctly.
  43. Incremental Placement:
    • Used in moderately sized or large cavity preparations
    • Placed in small increments(no larger than 2 mm thick)
    • Minimizes polymerization shrinkage
    • Permits adequate curing(light might not penetrate if increments are too thick)
  44. Other Factors of Clinical Handling of Composites:
    • Shelf life (2 to 3 years ) / refrigerator  / covered in a light-protected container
    • Dispensing and cross-contamination
  45. before placing composite restorations:
    • Clean tooth with non-fluoride and oil free paste
    • Isolate area to avoid contamination from water, saliva, or blood
    • No oil in air syringe
    • Do NOT use cavity liners with Eugenol….inhibits polymerization
  46. How do you Repair a Composite ?
    • Small fractures in a composite can be repaired
    • Repair of a new composite is optimum
    • New composite repairs better than old composite:
    •    New composites have a like chemical union
    • Finishing and polishing
    • Surface sealers:
    •    unfilled resins
    •    reseal margins that might have opened
    •    by polymerization shrinkage happens to fill small voids
  47. Indirect-Placement Composite Resins:
    • Laboratory-processed composites
    • Materials for indirect composites:
    •    Conventional composite
    •    Fiber-reinforced composite
    •    Particle-reinforced composite
    • Indirect chairside technique:
    •    CAD/CAM technology
    • replica (die) or form of a digital impression
  48. Glass Ionomers:
    • Use for cervically (Cl. V) eroded areas
    • Fluoride releasing
    • Chemically bonds with tooth
    • Packaging:
    •    Hand-mixed powder and liquid
    •    Encapsulated powder and liquid
    •    Two-paste systems
    • Sensitive to moisture uptake or loss during the first 24 hours of placement
    • Not wear resistant watch polishing
  49. Glass Ionomer Restorations uses?
    • For cementation of metal restorations and direct bonding of ortho brackets       
    • for class III and V restorations:
    •    as a liner and for dentin bonding;  post and     core and build-ups
  50. Glass Ionomer Restorations Advantages?
    • Chemically bonds to tooth (chemical adhesion)
    • May have fluoride in the powder (anticariogenic)
    • Can be placed in moist environments.
  51. Hybrid (Resin-Modified) Ionomers:
    • Hybrid of two dental materials: dental composites and glass ionomer cement
    • Improved physical properties
    • Dual cure materials
    • Stronger than regular glass ionomers
    • Easier to polish
    • More wear resistant
    • Fluoride release
  52. Nano-ionomers:
    • Improved esthetics
    • Increased wear resistance
    • Improved polishability
    • Fluoride release
    • Nanoparticle technology has been applied to the hybrid glass ionomer cements to improve their physical properties
  53. Compomers:
    • Are composite resins that have been modified with polyacid:
    •    The good qualities of the composite have been married with the fluoride release of the glass ionomer
    • Fluoride release
    • Light-activation chemicals included
  54. Giomers the Next Generation:
    • New hybrid restorative materials
    • Fluoride release at a slower and lower release than glass ionomers
    • Can be recharged with fluoride toothpaste or mouth rinse to act as a fluoride reservoir
    • Packaged as single paste syringes or flowables
Card Set
DHE132 LECTURE 3 quiz#2
DHE132 LECTURE 3 quiz#2