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63 Cards in this Set
- Front
- Back
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When all of the teeth in the dental arch are to be replaced it is called ________. When some, but not all, teeth in the arch are to be replaced, it is called _________.
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complete dentures
partial dentures |
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Ideal denture bases have several criteria including: (high/low) strength, (high/low) density, (easy/difficult) to manipulate, (good/moderate/poor) thermal conductivity, (difficult/easy) to repair and (good/poor) resistance to absorption of oral fluid.
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High
Low Easy Moderate Easy Good |
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Name the four different types of dentures.
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Removable Dentures
Fixed Dentures Fixed/removable Dentures Implanted-supported Dentures |
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What are the four methods of denture base processing?
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Heat-activated resins
Chemically-activated resins Light-activated resins Microwave energy-activated resins |
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What are the two techniques that fall under heat-activated resins and which one is the more commonly used method?
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Injection-molding technique
Compression-molding technique (MORE COMMONLY USED METHOD) |
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___________ technique and ___________ technique are both examples of denture base processing methods used with chemically-activated resins.
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Compression-molding
fluid resin |
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The _________ technique uses heat-activated resin like PMMA or thermoplastic polystyrene resin.
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injection-molding
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The injection-molding technique may provide slightly improved ____________ and a reduced risk of ___________.
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clinical accuracy
monomer vapor inhalation |
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What are the stages of polymer-monomer interaction?
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1) Sandy
2) Stringy 3) Doughlike 4) Rubbery or elastic 5) Stiff |
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The microwave energy-activated resins use specially-formulated _______ and a ______ in conventional microwave.
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PMMA resin
nonmetallic flask |
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Microwave energy-activated resins have the advantage of _______ and comparable ______________.
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speed
physical properties |
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In chemically-activated denture base resins, _______ is the activator.
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dimethyl-para-toluidine in the liquid
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____________ is not as complete as in heat-activated resins which can cause it to be a tissue _________ and can cause it to act like a _____, resulting in what?
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Degree of polymerization
irritant plasticizer will result in decreased transverse strength |
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What is the degree of polymerization of chemically-activated denture base resins?
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3-5%
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What are the uses of chemically-activated denture base resins?
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Denture Repair
Provisional Crowns Custom Trays |
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Chemically-activated denture base resins have (less/more) polymerization shrinkage (< ____ % linear) and (superior/inferior) color-stability than heat-activated resins.
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less
(<1% linear) inferior |
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Fluid resin technique uses _____-activated, (high/low) viscosity resin.
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chemically
low |
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What are the advantages of the fluid resin technique?
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Better soft tissue adaptation
Lesser chance of damage to denture base or teeth Simpler procedure Cheaper |
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What are the disadvantages of the fluid resin technique?
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Shifted teeth
Air entrapment Poor teeth-base bond Technique sensitivity Inferior physical properties |
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Light-activated denture base resin is a composite with a matrix of ______, ________ and _______, ________, and ______ as an initiator
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UDMA
microfine silica high Mw acrylic resin monomers acrylic filler beads camphoroquinone (initiator) |
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Processing stresses occur due to what?
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During the formation of the polymer
Thermal changes Improper mixing Poorly controlled heating |
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Porosities occur due to:
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Uncontrolled heating
Inadequate mixing of powder and liquid Insufficient material |
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High water absorption occurs due to:
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Expansion compensates for the shrinkage
Saturation in 17 days By the process of diffusion |
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Polymerization shrinkage of polymerized resin in approximately _____ % linear shrinkage ( _____ % vol shrinkage) whereas shrinkage of monomer is ____ % vol shrinkage.
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0.5%
6% 21% |
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Diluted Clorox solution is NOT recommended for what?
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metal partial dentures
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Suggestions to patients in reference to care of dentures should be:
(do/do not) use abrasive dentrifices or hot water to clean dentures (do/do not) use a soft brush and/or denture cleansers (do/do not) keep dentures moist when not in mouth |
do NOT
DO DO |
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____ % of all denture teeth are made of resin.
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60%
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______ absorb some of the stresses produced by mastication.
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Soft liners
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Denture adhesives are also called what?
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Denture adherents
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Denture adhesives are typically sold as ______, _______, _______ or ______ that are used as temporary measure to hold dentures firmly in place.
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creams
powders wafers strips |
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What are the components of denture adhesives?
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polymer, petroleum, mineral oil, silica, polyethylene oxide, and/or trace amounts of zinc
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________ can result due to chronic use of excess amounts of denture adhesives with trace amounts of zinc and may cause deleterious effects.
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Hyperzincemia
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When you know that your patient is using denture adhesives, it is important that you caution that patient to do what?
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Use SMALL amounts of the denture adhesive
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Chemically-activated soft liner liquid contains ___ - ____% plasticizers like _________. Plasticizers prevent and ________ over time.
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60-80%
dibutyl phthalate polymer chain entanglement leach out |
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Chemically-activated soft liners are considered (long/short) term while heat-activated soft liners are considered (long/short) term.
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SHORT (chemically activated)
LONG (heat-activated) |
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Concerning heat-activated soft liners, __________ are the most durable and adhesion to denture base is (poor/good).
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silicone rubbers
POOR |
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Heat-activated soft liners are acrylic resin polymers where the liquid contains _______ and ________.
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acrylic monomer
plasticizers |
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Resin denture teeth are (easier/more difficult) to adjust, have (less/more) impact resistance, (less/more) ductility, and (less/more) thermal shock resistance than porcelain denture teeth.
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EASIER
MORE MORE MORE (Apparently resin denture teeth are the caddys of the denture teeth world!) |
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Porcelain denture teeth have (better/worse) dimensional stability and (decreased/increased) wear resistance than resin teeth.
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BETTER
INCREASED |
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Porcelain teeth can cause wear of ______ and _______.
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opposing enamel
gold surfaces |
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The wear that porcelain teeth can produce to gold surfaces is specifically due to _________.
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abrasive damage
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Glass transition temperature is the temperature which __________ increases abruptly, indicating what?
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THERMAL EXPANSION COEFFICIENT increases indicating INCREASED MOLECULAR MOBILITY.
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Glass transition temperature is characteristic of what?
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glassy structures
(DUH, DUDE!) |
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What are used at temps above their glass transition temperature values and what is the purpose of going beyond this temp?
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MAXILLOFACIAL PROSTHETIC - AND IMPRESSION-MATERIALS
For the purpose of FLEXIBILTIY |
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What is used at temps below their glass transition temperature values and what is the purpose of not reaching this temp?
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RESTORATIVE COMPOSITE RESINS
For the purpose of being solid at oral temperatures and when subjected to hot foods/fluids |
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Resin denture teeth are:
(weak/tough) (soft/hard) (low/high) abrasion resistance (lower/higher) degree of cross-linking than denture base resin (chemically/mechanically) bond to denture base resin |
TOUGH
SOFT LOW HIGHER CHEMICALLY |
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Residual wax on resin denture teeth during processing can cause what?
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Teeth to be dislodged from denture base
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What is dough-forming time?
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Time required for resin matrix to reach dough-like stage should be LESS THAN 40 MINUTES (according to ADA Spec No. 12)
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Though the dough forming time requires that the resin mix reach the dough-like stage within no more than 40 minutes, typically it takes < _____ minutes for most products.
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LESS THAN 10 MINUTES
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Working time is the time that a resin mix remains in the ___________ stage and should be at least ______ minutes.
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dough-like
at least 5 minutes |
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Working time is affected by what and what can you do to prevent these effects?
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ambient temperature which can be avoided by storing in an airtight container in refrigerator and permitted to return to room temp before use
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What is the activator in the polymerization procedure?
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HEAT
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During the polymerization procedure, if ________ is heated above 60 C it will decompose.
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benzoyl peroxide
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During the polymerization procedure, ______ are released and ______ are converted to _______.
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FREE RADICALS
MONOMERS POLYMERS |
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What are the powder components of heat-activated denture base resins?
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prepolymerized spheres of PMMA
< 0.1% benzoyl peroxide initiator TiO2 opacifier |
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What are the liquid components of heat-activated denture base resins?
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Unpolymerized methyl methacrylate
<0.006% hydroquinone inhibitor 1-2 vol % glycol dimethacrylate for crosslinking |
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What component of heat-activated denture base resins is for crosslinking and is it apart of the powder or liquid?
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1-2 vol % gycol dimethacrylate
LIQUID |
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What component of heat-activated denture base resins is the inhibitor and is it apart of the powder or liquid?
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<0.006% hydroquinone
LIQUID |
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What component of the heat-activated denture base resins is that initiator and is it apart of the powder or liquid?
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<0.1% benzoyl peroxide
POWDER |
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What component of heat-activated denture base resins is the opacifier and is it in the powder or liquid?
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TiO2
POWDER |
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For heat-activated denture base resins the polymerization cycles are:
____°C for 9 hours OR ____°C for 2 hours, then _____°C for 1 hour OR ____°C for 90 minutes, the ____°C for 1 hour FOLLOWED BY: allowing resin and plaster/stone to do what? |
74°C
74°C, 100 °C 65°C, 100 °C allowed to reach a stable temperature |
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During the temperature rise of the polymerization of heat-activated denture base resin, the process is (exothermic/endothermic) AND above ____°C the process is accelerated.
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EXOTHERMIC
70°C |
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During polymerization of heat-activated denture base resin temperature rise, monomer boils at _____ °C and in thick portions of denture base, temperature of resin may rise above boiling causing what?
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100.8°C
POROSITIES |
