Dental Materials Science Flashcards
7 cards from real CDT practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 Dental Materials Science flashcards as text
What distinguishes a eutectic alloy from other metal alloys?
Answer: It has a single sharp melting point lower than either of its component metals
A eutectic alloy melts and solidifies at one specific temperature that is lower than the melting points of either component metal.
Type III gold alloy is preferred over Type I for fixed partial dentures primarily because of its:
Answer: Greater hardness and strength to withstand masticatory forces
Type III gold alloys have higher hardness and strength compared to Type I, making them suitable for load-bearing restorations like fixed partial dentures.
Which polymerization mechanism is responsible for the setting of chemically activated (self-cure) acrylic resin?
Answer: Free-radical addition polymerization initiated by a redox reaction
Self-cure acrylics use a redox initiator system (benzoyl peroxide + amine) to generate free radicals that drive addition polymerization at room temperature.
In dental porcelain, the feldspathic glass matrix contributes primarily to which optical property?
Answer: Translucency and esthetic vitality
The feldspathic glass matrix in porcelain transmits and scatters light in ways that mimic natural enamel translucency.
When mixing zinc phosphate cement, incremental addition of powder to liquid on a cool glass slab serves to:
Answer: Dissipate the exothermic heat and extend working time
Using a cool slab and adding powder incrementally dissipates the exothermic heat of the acid-base reaction, extending working time before the cement sets.
The water-powder ratio used when mixing gypsum products directly affects which property?
Answer: Strength, expansion, and setting time
Increasing the water-powder ratio reduces compressive strength, decreases setting expansion, and may alter setting time in gypsum products.
Which characteristic makes polyether impression materials distinct from vinyl polysiloxane in a moist clinical environment?
Answer: Polyethers are inherently more hydrophilic and capture detail better in the presence of moisture
Polyether impression materials are naturally hydrophilic due to their polar backbone, allowing better adaptation to moist tissues compared to VPS.