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Flashcards in Composites Deck (16)
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1
Q
  1. Understand the rationale for the production of metal-ceramic restorations
A

metal - M- good mechanical properties
ceramic - BCE - esthetics and wear performance

esthetic, strong/hard, tough

2
Q
  1. Describe the nature of ceramo-metallic bonding
A

Need

  1. Micromechanical Bonding (microabrasions on surface of alloy contribute to this)
  2. Chemical bonding (oxides in ceramic bond to oxide in alloy)
3
Q
  1. Define veneers
A

thin, semi translucent “shell” custom made to fit over the existing tooth - made from porcelain. very brittle on its own but when bonded securely to enamel it is strong, tough and durable

4
Q
  1. List the dental circumstances for which veneers have been claimed to be beneficial
A

closing spaces in teeth, restoring chipped teeth, whitening permanently stained, correcting uneven teeth

5
Q
  1. Describe the nature of bonding of veneers to enamel
A

held in place by adhesive resin. bonded to tooth enamel. veneer is permanently bonded and is extremely strong and durable

6
Q
  1. List the merits of veneers
A
very conservative (little or no tooth removal)
esthetics
7
Q
  1. Define composite materials
A

composite MATERIAL is where a constituent is added to the material to enhance its properties

ex resin-based dental composites
mainly polymer/ceramic combos

8
Q
  1. List the general constituents of dental resin composites
A
  • *dimethacrylate polymers

* *inorganic fillers

9
Q
  1. Discuss the function of dimethacrylate resins in dental resin composites
A

give rigid material and TOUGHNESS

10
Q
  1. List the types of fillers in dental composites
A

silica, barium glass, zirconia/silica (strength and wear resistance)

11
Q
  1. State the purpose of the coupling agent in dental composites
A

*** BONDING.

to covalently link the polymeric resin to the ceramic fillers. bonds polymer and filler to provide reinforcement

12
Q
  1. State the conditions required to achieve polymer reinforcement
A
  • adhesion btwn polymer and filler
  • filler should be more rigid (higher mod) than polymer
  • filler can act as load bearing component
13
Q
  1. State the effect of particulate inorganic fillers on dental composites
A

improve compressive strength
increase hardness
less setting shrinkage

14
Q

define composite

A

when complementary substances (metal, ceramic, glass, polymers) combine to produce structural and functional properties NOT present in any individual component. theyre better together than they are as individuals :’)

15
Q

one of two themes for composites - composite where separate materials are bonded together (2)

A
  1. metal ceramic restorations

2. veneers

16
Q

second theme - composite MATERIAL where a constituent is added to a material to enhance its properties

A

resin-based dental composites

mainly polymer/ceramic combos