DENT1014 & DENT1128: Casting & Investment Process

Lost Wax Casting (LWC) is used in...

• a) dentures

• b) partials

• c) crown & bridge

• d) ceramics

• e) all of the above

Lost Wax Casting (LWC) is the replacement of a formed wax shape, inside of an investing material, by another material (ie. metal).

• a) True

• b) False

Cast investments are...

• a) liquid, no,-heat resistant, crystalline, inorganic material

• b) solid, heat resistant, non-crystalline, inorganic material

• c) solid, heat resistant, crystalline, inorganic material

• d) liquid, heat resistant, crystalline, inorganic material

Investment expands...

• a) upon setting (setting expansion)

• b) if immersed in water while setting (hygroscopic expansion)

• c) when placed in high heat (thermal expansion)

• d) all of the above

Investment material must have sufficient expansion in order to compensate for wax and alloy shrinkage.

• a) True

• b) False

Before spruing, margins must be...

• a) overcontoured

• b) sealed

• c) short

• d) open

Sprue formers creates a channel that...

• a) directs molten metal from crucible into mold cavity

• b) allows for wax to escape

• c) provides reservoir of molten metal for casting

• d) all of the above

What size sprue former is used for Crown & Bridge at GBC?

• a) 6-10 gauge

• b) 8-10 gauge

• c) 4-18 gauge

• d) 4-6 gauge

The sprue must be attached to the thinnest cross section of the wax pattern.

• a) True

• b) False

What is the density of talmi?

• a) 7.8g/cm³

• b) 9.8g/cm³

• c) 8.8g/cm³

• d) 6.8g/cm³