dental materials

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dental materials
2011-04-18 12:02:34

ch. 16
Show Answers:

  1. multiple "monomer" chemically bonded together are _____ and ______ chain molecules
    large and long
  2. what is polymerization?
    act of forming polymers using CARBON BOND
  3. what kind of bond is polymerization
    carbon bond
  4. what are the two types of polymerization reactions?
    addition and condensation
  5. what is the most common polymerization reaction for dental materials?
    addition polymerization
  6. what are thre three stages of addition polymerization?
    • initiation
    • propagation
    • termination
  7. what opens the bond between carbon atoms of the monomer?
    free radicals
  8. what effect do free radicals have on the monomer?
    opens bond between carbon atoms
  9. what does the polymerization process produce
  10. too high of heat can cause the monomer to vaporize what does this cause?
  11. liquid monomer mixed with small polymer powder =??
  12. what does PMMA stand for?
    poly methyl methacrylate
  13. what is a polymerized resin called?
    poly methyl methacrylate
  14. dimensional change of acrylic resins are ______ shrinkage, __________ and ______ expansion
    • polymerization
    • watersorption
    • thermal expansion
  15. the thermal expansion of acrylic resins are ____ that of composite resins
  16. chmical cured acrylic resins are _____, _____, more ____ and less color stable
    • WEAKER
    • SOFTER
    • POROUS
  17. what keeps monomer of hte acrylic resin from evaporating?
  18. how much pressure is needed for an acrylic resin in a pressure pot?
    15-20 lbs of air
  19. what three things does pressure do for an acrylic resin during processing?
    • denser acrylic
    • stronger acrylic
    • less porosity
  20. t/f acryic teeth are porcelain
    FALSE-they are plastic
  21. denture teeth can be _____, _____ or _____?
    acrylic, plastic or porcelain
  22. what is the initiator of acrylic resins?
    benzoyl peroxide
  23. what is the liquid of the acrylic resins?
  24. chemical cure liquids have a _____ _____ as an activator
    tertiary amine
  25. what is the activator of the chemical cure liquid acrylic resins?
    tertiary amine
  26. what are the stages of polymerization reaction of acrylic resins? (know the right order)
    • sandy
    • stringy
    • dough
    • rubber
  27. when does polyerization for chemical cured resins?
    when liquid tertiary amine activates the benzoyl peroxide in the powder...then the free radicals develop
  28. when do free radicals develop?
    when polymerization occurs
  29. where is polymerization shrinkage most evident in dentures?
  30. what should soft liners be be cleaned with and why?
    benzalkonium chloride to reduce yeasts
  31. t/f long term soft liners do not form a good bond to new acrylic
    false- to OLD acrylic
  32. where are soft term soft liners are usually placed where?
  33. what are short term soft liners used for?
    tissue conditioners
  34. short term soft liners are applied to the primed denture base and reseated in pts mouth for what reason?
    border molding
  35. why do dentures become loose over time?
    bony ridge resorbing
  36. t/f porcelain dentures will cause more resorbing
    true-it is harder
  37. how are plastic (acrylic) teeth bonded to the acrylic base?
  38. what type of attachment does porcelain teeth need?
  39. do plastic teeth wear opposing natural or artificial teeth or the restorations?
    NO they do not!
  40. t/f the porcelain teeth do not bond to denture acrylic they need mechanical retention
    true dat
  41. when are porcelain teeth contraindicated?
    against natural teeth
  42. why would pt have more discomfort or denture sores or accelerted ridge resportion with porcelain teeth?
    transmits heavier occlusal forces
  43. porcelain teeth are _____, _____ and _____ resistant
    • hard
    • esthetic
    • stain resistant
  44. pastics are used for maxillofacial prostheses by what type of dentist?
  45. what is the process of chemical cured acrylic repair material?
    • sticky wax to hold pieces together
    • stone poured around prostheses
    • cut fracture line
    • wet and prime rougned with MONOMER
  46. during a repair of a denture what are the pieces held together with?
    sticky wax
  47. what are used to establish proper dimension between upper and lower arches?
    record bases
  48. what type of brush should a denture be cleaned with
    dneture brush
  49. what type of cleaner should be used for at home denture care?
    denture cleaner (liquid soap, mild hand soap)
  50. how can the calculus be softened at home on the denture?
    soak in 1:1 white VINEGAR and H2P (50-50)
  51. t/f you should not use undiluted household bleach on denture
  52. where will calculs accumulate on dentures?
    same places as natural dentition-max molars and man incisors
  53. in office how should dentures be cleaned?
    place in zippered plastic bag with dneture cleaning solution and place in ultrasonic cleaner