Dental Materials Final

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Dental Materials Final
2011-04-30 00:16:22

general questions thru dental cements
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  1. which organizations must approve dental materials for market?
    FDA-fodd and drug administrations
  2. what are the three dimensions of color?
    • Hue
    • Chroma
    • Value
  3. what is tooth color or mixes of color?
  4. what is intensity of color
  5. what is lightness or darkness (grayness) of color?
  6. what are the differences between posterior and anterior restorative material?
    • anterior=esthetics
    • posterior=strength
  7. what are the components of porcelain? 3
    • crystals of feldspar
    • alumina
    • silica
  8. what is the greatest reason for sealant failure?
  9. what is the greatest reason for porcelain failure?
    small cracks developed from occlusal loading
  10. what causes microleakage?
    • contaminants-blood, smear layer, oils
    • shrinkage
    • unbonded restorations
  11. what restorative material has the least microleakage?
    old alloys (due to corrosion blocking dentinal tubules)
  12. what restoration class is the occlusal and buccal of posterior teeth and the lingual pits of anterior teeth?
  13. what restoration class is the proximal surfaces of posterior teeth (includes the occlusal as well)
  14. what restoration class is the proximal surfaces of incisors and canines (no incisal angle)
  15. what restoration class is the proximal surfaces of incisors and canines, also the incisal angles?
  16. what restoration class is the gingival third of facial or lingual surfaces of the tooth?
  17. what restoration class is the cusp tips of posterior teeth and incisal edges of anterior teeth?
  18. what are the effects of a high alcohol mouthwash?
  19. when is a high alcohol mouthwash contraindicated?
    with xerostomia (drying)
  20. which four additives prevent dentinal hypersensitivity?
    • potassium nitrate (most common)
    • sodium citrate
    • strontium chloride
    • topical fluoride
  21. which topical additive acts against bacterial plaque?
  22. what is the main ingredient in a sealant?
    bisphenol A-glycidyl methacrylate (bis-GMA) or urethane dimethacrylate (UDMA)
  23. what is the energy mechanism for polymerization?
  24. which monomer is used in denture base?
    acrylic resin
  25. which dental materials are polymers
  26. what are adhesive wetting aids?
    acid etching
  27. what are three different etchants?
    • phosphoric acid
    • polyacrylic acid
    • hydrophloric acid
  28. what is the most commone etchant and what is used for?
    phosphoric acid=sealants
  29. what etchant is used for glass ionomers?
    polycarylic acid
  30. what etchant is used for porcelain?
    hydrophloric acid
  31. what is the purpose of bonding?
    to provide a MECHANICAL and CHEMICAL BOND for RESIN MATERIALS (or combo of both)
  32. what 6 things increase the rate of abrasion?
    • speed and pressure
    • size irregularity and hardness
    • number of particles
  33. _____ speed = _____ abrasion
    • higher
    • more
  34. what will increasing speed and pressure do to abrasion?
    increase rate of abrasion
  35. what are adverse reactions of abrasives/polishes? 3
    • fluoride-rich enamel layer is polished away
    • polish away contact and margins of restorations
    • exposed cementum or demineralized enamel removed
  36. what is used for the final polish for the majority of restorations?
    tin oxide
  37. why should one polish fillings? 3
    • improves esthetics
    • improves tissue health
    • increases longevity of fillings
  38. how does heat affect the dental pulp?
    detrimental to the pulp
  39. what is used in the lab to polish gold?
    • burlew wheel on slow speed handpiece
    • rouge on rag wheel
  40. which cement bond to teeth? 3
    • zinc polycarbonxylate
    • resin glass ionomer (hybrid) cement
    • glass ionomer have a weak bond to tooth
  41. which cement has chmical adhesion? 2
    • glass ionomer cements
    • resin cements
  42. which cement has mechanical retention between tooth and crown? 2
    • zinc phosphate
    • zinc polycarboxylate
  43. what are the differences between high and low strength bases/liners?
    • high strength base/liner-provides THERMAL insulation and MECHANICAL support for restorations
    • low strength base/liner-PULP capping, stimulates secondary dentin, barrier between pulp and restoration
  44. name the fluoride releasing cements
    • glass ionmer
    • hybrid ionomer
  45. what are the purposes of bases/liners?
    • liners-seal dentin or medicate the dentinal pulp
    • bases-provide thermal insulation or mechanical protection of the dental pulp
  46. which dental cement sooths pulp tissue?
    zinc oxide eugenol
  47. what are the characteristics of a base?
    • bases are used to provide THERMAL INSULATION OR MEHCANICAL PROTECTION for the dental pulp
    • includes ALL CEMENTS because cements are poor thermal conductors and have adequate compressive strength
  48. which cement makes reparative dentin?
    calcium hydroxide
  49. what are the porperites of cements that allow them to be used as bases?
    poor thermal conductors, adequate compressive strength (they insulate and protect the pulp)
  50. what is used to clean zinc oxide eugenol instruments?
    alcohol or oragne solvent
  51. what is used to clean zinc phosphate cement?
    ultrasonic cleaner or solution of baking soda and water