Untitled Flashcard Set

What are the main advantages of the combination of porcelain and metal for fixed crown and bridge prosthodontics?

Strength from the metal + esthetics from the porcelain.

The metals used as the core for PFM crowns are alloys that will form a (an) __ layer as the metal is heated.

Oxide layer.

The first layer of porcelain applied to the metal during fabrication of porcelain-metal restorations is known as the __.

Opaque layer.

The best arrangement for the coefficient of thermal expansion between porcelain and metal is for the porcelain to have __ thermal expansion than the metal.

Slightly lower.

Computer-assisted machining for crown and bridge techniques does not require that dies be poured or a temporary made. True or False?

A. True

When should a shade of a tooth be taken?

Before tooth preparation, with the tooth hydrated and in natural/neutral lighting.

Shade tabs should be moistened and held adjacent to the teeth to be matched. True or False?

A. True

___ is the fusion of ceramic particles at their borders by heating them to the point of beginning to melt.

Sintering.

A CAD/CAM machined crown uses an optical scanner to __.

C. make the impressions (digital images).

Noble dental casting alloys do not require any gold but must contain at least 25% noble metals by weight. True or False?

A. True

One of the noble metals used for dental casting alloys is platinum. True or False?

A. True

Chromium is a base metal with the highest incidence of allergic response. True or False?

B. False (Nickel has the highest).

___ is used when gold castings are soldered to remove surface oxides so the solder can flow freely.

Flux.

Which metal is added to gold and silver solders to lower the melting range?

Tin.

What are silver-based solders primarily used for in dentistry?

Joining or repairing metal components (frameworks, appliances).

What is dental wrought wire primarily used for in dentistry?

Orthodontic wires, clasps, splints, and appliance components.

Why would zinc be added to a base-metal mixture?

B. Reduces oxidation when the alloy is cast.

24 Karat =

100% gold.

12 Karat =

50% gold.

__ Alloy composed of non-noble metals

B. Base-metal alloy.

__ A solid compound made of two or more elements, one of which is a metal

A. Alloy.

__ Alloy containing at least 60% noble metals, 40% of which must be gold

D. High-noble metal.

__ Classification of metal based on its high cost

E. Precious metal.

__ Alloy composed of metals that do not corrode readily; at least 25% must be noble metals

C. Noble alloy.