Dental Materials

Average particle size of powdered gold is________________? A. 10 umB. 15 um C. 30 um D. 0.1 um

The pure form of gold used in dentistry is known as___________________? A. Cohesive gold B. Non cohesive gold C. Class I casting gold D. Class IV casting gold

Electralloy is an alloy of________________? A. Gold and Platinum B. Cobalt and ChromiumC. Gold and Calcium D. Tin and chromium

The carat for Au foil used for restorations is_______________? A. 18 B. 20 C. 22D. 24

Direct filling gold formed by electrolytic precipitation is called by all the terms EXCEPT______________? A. CrystallineB. Granular gold C. Mat gold D. Sponge gold

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 layerC. Presence of copper D. Formation of excess oxides

Powdered gold is___________________? A. Made by a combination of chemical precipitation and atomization B. Made by electrolytic precipitation C. Made by beating pure gold at high temperatures D. Made by milling pure gold ingots

Which of the following is true about direct filling gold______________? A. Properly condensed mat gold has no voidsB. Whatever may be the type voids are inherent C. Voids can be avoided with manual condensation D. None of the above

The malleting force is directed______________? A. Perpendicular to the walls B. Parallel to long axis of crownC. 45° to the wall D. None of the above

Pitting of direct filling old restoration usually results from_________________? A. Using contaminated gold foil B. Poor finished preparationC. Improper stepg of condenser point D. Using small condenser point