31. The major component of zinc phosphate cement is_____________?
A. Zinc oxide
B. Phosphoric acid
C. Zinc
D. None of the above
✅ The correct answer is option A. Zinc oxide.
Dental Materials
32. Torsional force is_______________?
A. Compression
B. Tensile force
C. Shear
D. Transverse bending force
✅ The correct answer is option C. Shear.
33. Absorption of mercury in the human body occurs least from_____________?
A. Lungs
B. Gastro-intestinal Track
C. Skin
D. Kidneys
✅ The correct answer is option D. Kidneys.
34. Which cement is irritating to the pulp ?
A. Carboxylate cement
B. Zinc oxide-eugenol cement
C. Zinc phosphate
D. Ethoxybenzoic acid
✅ The correct answer is option C. Zinc phosphate.
35. What is the most frequently used restorative material ?
A. Silicate
B. Amalgam
C. Composite
D. Gold
✅ The correct answer is option B. Amalgam.
36. Which of the following is common to both zinc eugenol cement and polycarboxylate cement?
A. Polyacrylic acid is liquid
B. Chemical bond to tooth structure
C. Chelation
D. Substitution o eugenol by EBA to increase strength of cement
✅ The correct answer is option C. Chelation.
37. During amalgamation, trituration is done to_____________?
A. Dissolve the alloy in mercury
B. Coat the alloy particle with mercury
C. Remove excess mercury from the amalgam
D. Dissolve Hg in alloy
✅ The correct answer is option B. Coat the alloy particle with mercury.
38. Which of the following constituents of amalgam alloy decreases expansion____________?
A. Copper
B. Zinc
C. Silver
D. Tin
✅ The correct answer is option D. Tin.
39. The setting time of ZnPO4 cement can be retarded by_____________?
A. mixing more powder to the liquid
B. mixing powder to liquid, checked by water
C. slower addition of powder to liquid
D. faster addition of powder to liquid
✅ The correct answer is option C. slower addition of powder to liquid.
40. By increasing the percentage of which metal, the strength and hardness of amalgam increases_____________?
A. Ag
B. Zn
C. Cu
D. Hg
✅ The correct answer is option C. Cu.