Dental Materials MCQs
Dental Materials MCQs test the understanding of restorative and preventive materials used in dentistry. Topics include dental amalgam, composite resins, glass ionomers, impression materials, and adhesives. These MCQs are valuable for BDS and MDCAT students aiming to grasp the properties, manipulation, and clinical use of dental materials.
Q: To prevent microleakage, dental sealants should be placed under dry conditions using rubber dam isolation
A) Rubber dam
B) Moist cotton
C) Heat drying
D) Wet field
✅ Correct Answer: A
Explanation: Moisture contamination reduces the bond strength of sealants.
Q: When using a glass ionomer liner, it should be placed in a thin layer and light-cured if resin-modified to achieve optimal bonding
A) Light-cured thin layer
B) Thick layer applied
C) Bulk filled
D) No curing needed
✅ Correct Answer: A
Explanation: Thin, cured layers ensure integrity without interfering with final restoration.
Q: Fracture toughness of a dental material refers to its ability to resist crack propagation under stress
A) Thermal resistance
B) Color change
C) Crack resistance
D) Compressive stress
✅ Correct Answer: C
Explanation: Fracture toughness is essential for durability under load.
Q: Resin composites should be added in increments of 2 mm or less to avoid polymerization shrinkage stress
A) Post-curing
B) Incremental layering
C) Single fill
D) Bulk placement
✅ Correct Answer: B
Explanation: Incremental layering reduces internal stress and improves cure.
Q: The coefficient of thermal expansion in dental materials must closely match natural teeth to avoid marginal gaps
A) Hardness
B) Match enamel
C) Low cost
D) Improve color
✅ Correct Answer: B
Explanation: A matching thermal expansion coefficient prevents thermal-induced failures.
Q: In endodontic procedures, gutta-percha is the most commonly used material for obturating the root canal space
A) Composite
B) MTA
C) Zinc phosphate
D) Gutta-percha
✅ Correct Answer: D
Explanation: Gutta-percha is biocompatible and provides a good seal when used with sealers.
Q: During casting, shrinkage of molten metal is compensated by using a properly calculated sprue and reservoir system
A) Surface porosity
B) Overcooling
C) Sprue system
D) Underheating
✅ Correct Answer: C
Explanation: Proper casting design prevents shrinkage voids.
Q: The use of calcium hydroxide liners beneath deep restorations stimulates the formation of reparative dentin
A) Causes sensitivity
B) Weakens enamel
C) Enhances bonding
D) Stimulates dentin
✅ Correct Answer: D
Explanation: Calcium hydroxide promotes pulp healing and tertiary dentin formation.
Q: Gypsum products stored in open air tend to absorb moisture from the environment, resulting in slower and weaker setting
A) Water loss
B) Faster set
C) Stronger crystals
D) Moisture contamination
✅ Correct Answer: D
Explanation: Humidity degrades the performance of gypsum powders.