dental materials

Card Set Information

dental materials
2011-02-04 08:23:06
chapter five

week three
Show Answers:

  1. What type of bonding agent is more important to dentin than enamel, contains hydrophilic groups to penetrate wet etched dentin, and mechanically bonds to dentin?
  2. What type of bond is a chemical bond, contains a hydrophobic group that chemically bonds to the composite resin, and bonds mechanically to metals/porcelains?
    resin adhesive
  3. phosphoric acid etching of both enamel and dentin with a separate step that includes rinsing off the acid and lightly drying the tooth
    total-etch or universal etch
  4. layer formed be collagen fibrils, and ty dentin bonding resin, the etched dentin surface is called what
    hybrid layer
  5. The bond that links dentin with the restorative material is accomplished through what layer?
    hybrid layer
  6. Many of the current all-etch bonding agents are desingated as universal bonding agents, what does this mean?
    they are suitable for bonding on all enamel, dentin, and restorative surfaces
  7. What type of bonding system has one and two bonding systems that have been developed that incorporate acidic groups in the boning agent that will etch enamel and dentin and allow penetration of the resin without the need for rinsing and drying?
    self-etching bonding agents
  8. What are 2 drawbacks of self-etching primers?
    • they do not adequately etch uncut enamel
    • can't be used in direct bonding to unprepared enamel such as sealants or veneers
  9. type of cure in which a chemical reaction occurs when two resins, a base and with chemical activators and a catalyst are mixed together
  10. cure that uses a light in the blue wave range to activate a chemical that sets off the polymerization reaction or curing process
  11. cure that uses a combination of self and light-cure ingredients, these resins can be activated by light or can cure chemically without application of curing light
  12. What type of bond is a resin to resin (composite)
  13. What type of bond is resin to metal or porcelain?
  14. is a dentinal or enamel bond stronger?
  15. How long must you re etch an enamel bond if it becomes contaminated?
    15 seconds
  16. The following things make up what layer? tooth debris, plaque, bacteria, pellicle, saliva, blood
    smear layer
  17. In the all etch technique, should you etch dentin or enamel first?
    • enamel for 10
    • then dentin for 10
  18. What happens if you etch dentin for longer than 20 seconds?
    • decreases bond strength
    • causes post treatment hypersensitivity
  19. Why is it important to keep the dentin moist after rinsing the etch for 10 seconds to remove excess water?
    it keeps the collagen fibers fluffed
  20. What causes the following to happen? occlude dentinal tubules, block penetration by dentin bonding resins, dentin/resin interface fracture
    collagen fibers have collapsed
  21. _________ dissolved in resin allow resin penetration (moist dentin) and collagen fibrils into the dentinal tubules
  22. leakage of fluids and bacteria between tooth and restoration
  23. What are 4 causes of microleakage?
    • contamination (blood, saliva, smear layers, oil)
    • shrinkage
    • unbonded restorations
    • coefficient of thermal expansion
  24. What are three of the results of microleakage?
    • recurrent decay
    • staining
    • post operative sensitivity from percolation
  25. Pain of hypersensitivity common with bonded restorations is felt through what?
    odontoblasts in pulp at dentinal junction
  26. how far do odontoblasts extend in the dentinal tubule?
    1/3 of the way in
  27. dentinal tubule contains a column of pulpal fluid and the dentinal fluid will move with pressure changes, what is this called?
    hydrodynamic theory of tooth sensitivity
  28. pressure receptors in the odontoblast only illicit what type of response?
  29. What is the primary reason for hypersensitivity?
    unsealed dentinal tubules
  30. what are three contributing factors to dentinal hypersensitivity?
    • over drying
    • over etched
    • composit is cured in too large of increments, causin contraction stress on tooth