A. Impurities in gold
B. Improper venting
C. A and B
D. None of the above
Related Mcqs:
- In type II gold alloys _______ Karat gold is used?
A. 24 K
B. 22 K
C. 18 K
D. 10 K - Gases dissolved in molten metals are liberated when cooled giving rise to________________?
A. Suckback porosity
B. Gas inclusion porosity
C. Localized shrinkage porosity
D. Microporosity - When Gold fused with porcelain is fired at very high temperature greenish discoloration of cervical margin is due to________________?
A. High firing temperature
B. Disintegration of opaque layer
C. Presence of copper
D. Formation of excess oxides - Addition of large amounts of platinum to a casting gold alloy will________________?
A. Decrease its strength and ability to be hardened
B. Decrease its tarnish resistance
C. Increase its fusion temperature
D. Redden the alloy - Reduction in the fusion temperature of dental gold casting alloys is caused by presence of______________?
A. Platinum
B. Copper
C. Silver
D. Gold - Gold content of an 18 carat alloy is______________?
A. 25%
B. 50%
C. 75%
D. 100% - Within an hour after cementation of cast gold onlay patient complains of shooting pain every time the teeth comes together Most probable explanation is ______________?
A. Supracocclusion of restoration
B. Retained cement in gingival sulcus
C. Excess acid in mix
D. Galvanic current caused by gold onlay occluding with a large restoration - Nickel is added to wrought gold alloys as______________?
A. Strengtherner
B. Hardener
C. Whitens the alloy
D. Scavenger - Which of the following cast gold alloys is used for fabricating partial denture frameworks______________?
A. Type I – Soft
B. Type II – Hard
C. Type III – Hard
D. Type IV – Extra Hard - The contraction of gold alloy on solidifying is approximately_____________?
A. 0.4%
B. 1.4%
C. 2.4%
D. 3.4%
