21. Which of the following is the main constituent of porcelain__________________?
A. Feldspar
B. Kaolin
C. Quartz
D. Clay
✅ The correct answer is option A. Feldspar.
Dental Materials
22. The chief advantage of zinc phosphate cement is its___________?
A. Good compressive strength
B. Film thickness
C. Lack of irritation
D. Low solubility
✅ The correct answer is option B. Film thickness.
23. Outstanding clinical performance of dental amalgam restoration is related to its____________?
A. Compressive strength
B. Tensile strength
C. Corrosion
D. Creep
✅ The correct answer is option A. Compressive strength.
24. In a high copper amalgam the phase, which is eliminated is_______________?
A. Gamma 1
B. Gamma 2
C. Gamma 1 and 2
D. No phase is eliminated
✅ The correct answer is option B. Gamma 2.
25. Admixed high copper alloy powder contains_________________?
A. 9-20% copper
B. 13-20% copper
C. 9-30% copper
D. 13-30% copper
✅ The correct answer is option A. 9-20% copper.
26. Which of the following do polycarboxylate and GIC have in common ?
A. Polysiloxane
B. Phosphoric acid
C. Polyacrylic acid
D. Ion leachable glass
✅ The correct answer is option C. Polyacrylic acid.
27. All of the following are true for traditional solution liner, except_________________?
A. It is not necessary in moderately deep cavities under glass ionomer restoration
B. Have Film thickness of 1 – 50 microns
C. Do not provide thermal or electric insulation
D. Protect the pulp from reaction products leaching out of restoration
✅ The correct answer is option B. Have Film thickness of 1 – 50 microns.
28. The solid solution of silver and mercury is called_______________?
A. y1
B. y2
C. B1
D. y
✅ The correct answer is option A. y1.
29. Which of the following silver amalgam alloy have the maximum strength________________?
A. Lathe cut
B. Spherical
C. Admixed
D. Single composition
✅ The correct answer is option D. Single composition.
30. Age hardening is a process done at______________?
A. Heating up to 200 – 450°C for 15 – 30 min and quenching in water
B. Heating at 700°C for 10 – 15 min and quenching in water
C. Heating at 700°C for 1 hour and quenching in water
D. Heating above 700°C for 30 min and quenching in water
✅ The correct answer is option A. Heating up to 200 – 450°C for 15 – 30 min and quenching in water.