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33 Cards in this Set

  • Front
  • Back
3 types of polymers:
Heat active
Chemically
Light
Which is for dentures, acrylic teeth, crown bridge?
Heat
3 types of polymers:
Heat active
Chemically
Light
which is for denture repair, relines, ortho appliance, pouring resin
chemical
3 types of polymers:
Heat active
Chemically
Light
Whch is composite, adhesive, Glass ionomer cements?
Light
3 TOPOLOGICAL classifications of polymers?
linear, cross linked, or branched
2 monomer distrubtion classifcations:
homo or co - polymers
The supramolecular structure of a polymer is either Amorphous or semicrystalline. describe each
amorphous - coiled, irregular shape opf chains
semicryst - domains w/ regular structure
Describe thermoplastic polymers ( cross links, properties)
NOT cross linked - linear/branched.
Flow when heated
Desscribe thermosetting polymers (cross links, properties)
Cross linked, Do not melt/reshape - decompose in ehat
what type of polymer exhibits recovery under low strains?
elastomer
Describe degree of saturation of a compound that is an elastomer.
UNSATURATED
What is a thermoplastic elastomer? 2 examples
behaves like rubber at RT, but w/ heat loosens, behaves thermoplastic. Latex, synthetic rubbers
Polysaccs like alginate and polyisoprenes are examples o fwhat?
natural polymers
What are alginates used for? what type of polymer are they?
impressions - natural polymer
2 types of synthetic reactions for polymers
addition and step growth
What types of synethic polymers have higher MW?
addition reaction products
what types of synthetic polymers have lower MW?
stepgrowth polymer
A free radical product's active center (for reaction) is what?
the free radical
a cationic reaction for synthetic polymer's active center is what? it's propagation site?
ACID, w/ a positive propgation site
an anionic reaction for synthetic polymer's active center is what? it's propagation site?
Nucleophile, w/ negative prop site
what is the difference between a retarder and an inhibitor
retarder slows, to make less reactive products
inhibitor STOPS - makes no future reactions
4 advantages of MMA?
able to be manipiulated
Good mech properties (strong/wear resist)
Biocompatible (taste/odorless, non-toxic
Good esthetic properties
2 negatives of MMA?
exothermic reaction
Flammable
(also may be irritant?
3 reasons to add a polymer inhibitoir
prolong setting time
decrease light sensitivity
extend shelf life (prevent spontaneuos polymerzation)
For PMMA, cross linking is
Positive (3)
Negative (1)
+
1 - hard/stiff
2 - crazing resistance
3 - increase thermal resistance
(-)
brittle
what is the use of plasticizing?
reline dentures?
3 classifications of polymerss based on initiation reactions?
heat, chemical, light
3 classifications of polymerss based on initiation reactions: heat/light/chemical. each has how many comoonents?
heat - 2
chem - 2
light - 1
What are the 2 components of a heat-activated polymer?
powder - PMMA prepolymer
Liquid - MMA/cross link/additive/regulatro
in a 3:1 ratio
why is a regulator needed for a heat activated reaction?
if it heats too fast, it will be porous
what are the 2 components of a chemcially activated initatior
powder - PMMA pre/copolymer DIBENZOYL PEROXIDE
liquid - MMA, cross link, inhiitor, accelerator, UV absorbers
What is a disadvantage of a chemically activated polymer (vs heat)
LESS color stability
what is camphorquinone?
light initiating system
What is BIS-GMA
dimethacylate light iactivated resin