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: The most commonly used material for fabrication of custom trays in complete denture procedures is auto-polymerizing acrylic resin
A) Light-cure composite
B) Auto-polymerizing acrylic
C) Thermoplastic sheet
D) Polycarbonate
✅ Correct Answer: B
Explanation: Auto-polymerizing acrylic is preferred due to ease of manipulation and cost-effectiveness.
Q: During the setting of gypsum, the chemical reaction leads to formation of interlocking needle-like crystals of calcium sulfate dihydrate
A) Expansion
B) Crystallization
C) Heat absorption
D) Water loss
✅ Correct Answer: B
Explanation: Crystallization forms the basis of gypsum hardening and setting.
Q: The main disadvantage of using amalgam as a restorative material is its unaesthetic metallic appearance
A) Metallic color
B) High cost
C) Unpleasant odor
D) Brittleness
✅ Correct Answer: A
Explanation: Amalgam is strong and durable, but its color does not match natural teeth.
Q: Etching of enamel with phosphoric acid increases surface energy and creates micro-porosities for better bonding
A) Reduces bonding
B) Prevents drying
C) Promotes leakage
D) Enhances retention
✅ Correct Answer: D
Explanation: Acid etching creates a rough surface which improves mechanical bonding.
Q: In glass ionomer cements, fluoride release helps in the prevention of secondary caries around restorations
A) Reduces bond
B) Increases acidity
C) Prevents caries
D) Weakens cement
✅ Correct Answer: C
Explanation: Fluoride release offers long-term protection against bacterial decay.
Q: The role of silane coupling agent in composite resin materials is to enhance the bond between the resin and the filler particles
A) Increase color
B) Reduce wear
C) Strengthen filler
D) Bond filler to resin
✅ Correct Answer: D
Explanation: Silane chemically links inorganic filler and organic resin matrix.
Q: For accurate reproduction of oral tissues, elastomeric impression materials like addition silicone are highly preferred in fixed prosthodontics
A) Addition silicone
B) Plaster
C) Reversible hydrocolloid
D) ZOE
✅ Correct Answer: A
Explanation: Addition silicones are dimensionally stable and precise.
Q: The setting reaction of polycarboxylate cement involves chelation of carboxyl groups with calcium ions in tooth structure
A) Ionic bonding
B) Mechanical retention
C) Hydrogen bonding
D) Covalent bonding
✅ Correct Answer: A
Explanation: Ionic interaction ensures chemical adhesion to enamel and dentin.
Q: Increased powder-to-liquid ratio in dental cements generally results in higher strength and lower solubility
A) Increases porosity
B) Weakens cement
C) Slows setting
D) Improves strength
✅ Correct Answer: D
Explanation: More powder leads to a denser and stronger set cement.
Q: Compressive strength of dental materials is particularly important for posterior restorations that endure heavy masticatory forces
A) Compressive resistance
B) Solubility
C) Thermal expansion
D) Aesthetic value
✅ Correct Answer: A
Explanation: Posterior teeth need materials that can resist crushing forces.