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71 Cards in this Set
- Front
- Back
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What's the term for a removable prosthesis intended to replace teeth and associated oral structures
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denture
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When all the teeth in an arch are replaced, it's a (complete/partial) denture
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complete
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When only some of the teeth in the arch are replaced, it's a (complete/partial) denture
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partial
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The part of the denture that do not replicate teeth is called the denture __
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base
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T of F, dentures should be low density
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T
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T or F, dentures should absorb oral fluid
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F
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What are the 4 methods of denture base processing?
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heat-activated
chemically-activated light-activated microwave energy-activated |
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What are the two types of heat activated denture base resins and which is MOST common?
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compression-molding (most common)
injection-molding |
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What are the two types of chemically-activated resins
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compression-molding
fluid resin |
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The powder in heat-activated denture base resin contains:
prepolymerized spheres of ___ < 0.1% __ peroxide initiator TiO2 as a ____ |
PMMA, benzoyl, opacifier
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The following are the liquid components of heat-activated denture base resin:
(pre/un)polymerized methyl methacrylate < 0.00_% hydroquinone inhibitor 1-2 vol% glycol dimethacrylate for __-linking |
un, 6, cross
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What is the polymer:monomer ratio by volume?
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3:1
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polymer and monomer interact for form dough-like stage in less than how many minutes?
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10
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Name the 5 phases of consistency that the polymer/monomer mix goes through
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sandy
stringy dough-like rubbery or elastic stiff |
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The time required for resin mix to reach dough-like stage should be LESS than __ min according to ADA spec # __. But most products are less than __ min
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40, 12, 10
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The working time is defined as the time that a resin mix remains in the __ stage. This should be at least 5 min
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dough-like
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T or F, working time is unaffected by ambient temperature
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F
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Resin dough should be stored in a (cold/warm) environment and allowed to return to room temp before working
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cold
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What is the activator in heat-activated resins?
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heat
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Above __C, benzoyl peroxide will decompose
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60
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T or F, heat creates free radicals and converts monomer to polymer
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T
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The following are the 3 polymerization cycles:
__C for 9 hrs 74C for __ hrs, then 100C for __ hr 65C for 90 min, then __C for 1 hr |
74
2, 1 100 |
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resin is a (good/poor) thermal conductor
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poor
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The resin curing process by heat-activation is (endo/exo)thermic, above __C the process is accelerated
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exo, 70
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Monomer in heat-activated resins boils at what temp?
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100.8C
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If temp raises above boiling in heat-activated denture base resins, what can form?
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porosities
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T or F, injection-molding reduce the risk of monomer vapor inhalation
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T
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T or F, injection-molding technique uses heat-activated resin like PMMA
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T
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Microwave energy-activated uses specially formulated PMAA resin and a (true/non)metallic flask in a (special/conventional) microwave
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non, conventional
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Microwave energy-activated denture base resins have the advantage of ___ and have comparable physical properties
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speed
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What is the activator in chemically-activated denture base resin?
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dimethyl-para-toluidine
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Degree of polymerization is (more/less) complete in chemically than heat-activated
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less
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How much unreacted monomer is left over in chemically activated resin and what can it do?
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3-5%
tissue irritant act like plasticizer, resulting in lower transverse strength |
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Chemically-activated denture base resins can be used for what 3 purposes?
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denture repair
provisional crown custom tray |
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Chemically-activated have (more/less) polymerization shrinkage
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less
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which has better color-stability, heat or chemically activated?
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heat
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What technique uses chemically-activated low viscosity resin?
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fluid resin technique
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The following are properties of fluid resin technique:
(better/worse) soft tissue adaptation (less/more) chance to damage denture base or teeth (harder/easier) procedure (more/less) expensive |
better, less, easier, less
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Which of these is NOT a disadvantage of the fluid resin technique?
shifted teeth air entrapment poor teeth-base bond technique insensitive inferior physical properties |
technique insensitive (should be SENSITIVE)
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What is the matrix in light-activated resin?
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UDMA, microfine silica and high Mw acrylic resin monomers, acrylic filler beads, and camphoroquinone
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camphoroquinone serves what purpose in light-activated resins
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initiator
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T or F, special finishing and polishing is required with light-activated resin
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false, conventional is fine
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Polymerization shrinkage of polymerized resin is 0._% linear (6% vol shrinkage) whereas the monomer is __% vol shrinkage
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5, 21
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There is a slide that lists some things and I'm not clear on the significance or what he was going for so they're just listed here as the answer
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high water absorption:
-by process of diffusion -saturation in 17 days -expansion compensates for shrinkage porosities: -uncontrolled heating -inadequate mixing of powder and liquid -insufficient material Processing stress -during formation of polymer -due to thermal changes -improper mixing -poorly controlled heating |
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Denture base resins have:
(high/low) strength (high/low) flexibility (high/low) brittleness (high/low) hardness (high/low) fatigue strength (high/low) thermal conductivity |
low
high high low high low |
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Which is NOT recommended for dentures:
keep moist when not in mouth don't use abrasion or heat to clean use soft toothbrush use clorox for metal partials |
use clorox for metal partials
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They now have a CAD/CAM like technology for dentures
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COOL!
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What % of denture teeth are made of resin?
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60
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resin teeth are:
tough, soft, and have (low/high) abrasion resistance |
low
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T or F, denture teeth have HIGHER degree of crosslinking than denture base resin
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True
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denture teeth bond to denture base resin via (physical/chemical) bonds
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chemical
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T or F, residual wax on resin teeth during processing will cause teeth to dislodge from denture base
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T
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Compared to porcelain teeth, denture teeth:
(easier/harder) to adjust (more/less) impact resistance (more/less) ductility (more/less) resistance to thermal shock |
easier, more, more, more
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Compared to resin teeth, porcelain teeth:
(worse/better) dimensional stability (increased/decreased) wear resistance |
better, increased
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T or F, porcelain teeth can cause damage to opposing enamel and gold surfaces
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T
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What absorbs some stresses produced by mastication?
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soft liners
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chemically-activated soft liners are considered (long/short) term
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short
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What are the components of chemically-activated soft liners?
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poly methyl methacrylate
poly ethyl methacrylate Liquid had 60-80% plasticizers like dibutyl phthalate |
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What is the plasticizer in chemically-activated soft liners and what does it do?
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dibutyl phthalate
prevent polymer chain entanglement PROBLEM: they leach out over time! |
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Silicone rubbers are (least/most) durable heat-activated soft liners
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most
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What is in the liquid of acrylic resin polymers of heat-activated soft liners?
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acrylic monomer and plasticizers
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Silicone rubber heat-activated soft liners have (poor/good) adhesion to denture base
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poor
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What is the definition for the temp at which thermal expansion coefficient increases abruptly, indicating increased molecular mobility?
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Tg (actually the g is a subscript here)
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Tg is also known as the __ __ temperature
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glass transition
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Maxillofacial prosthetic and impression materials are used at temps (above/below) their Tg values so that they are (flexible/rigid)
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above, flexible
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Restorative resin composites are used at temps (above/below) their Tg so they will be solid at oral temp and when subjected to hot food and fluid
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below
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Denture adhesives are also called denture ___ and are sold in what 4 forms?
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adherents
creams, powder, wafer, strips |
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denture adherents are meant to be (permanent/temporary)
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temporary
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Denture adhesives contain polymer, ___, mineral oil, silica, polyethylene __ and trace amounts of what metal?
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petroleum, oxide, zinc
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Why should patients use small amounts of denture adherents?
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They can cause hyperzincemia due to chronic use of excessive amounts and may have deleterious effects
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What 4 materials can be used as maxillofacial prosthetics?
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latexes, silicone rubber, polyurethane, vinyl plastisols
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