CCE Substructure for Ceramics 2

Question 1

Which metal alloy type offers the highest bond strength with ceramic veneers due to its oxide layer formation?

Accepted Answer

Base metal alloy

Answer

Base metal alloys form a robust oxide layer that chemically bonds to dental porcelain, providing superior ceramic adhesion.

Question 2

When designing a metal substructure, the recommended minimum metal thickness for strength without excess bulk is:

Accepted Answer

0.3–0.5 mm

Answer

A metal coping thickness of 0.3–0.5 mm provides adequate rigidity to support the overlying ceramic without adding unnecessary bulk.

Question 3

What purpose does the oxidation (degassing) firing serve in preparing a metal substructure for porcelain?

Accepted Answer

It removes surface contaminants and forms an oxide layer

Answer

Oxidation firing burns off organic contaminants and creates a controlled oxide layer that promotes chemical bonding with the opaque porcelain.

Question 4

A connector on a fixed partial denture (FPD) substructure must have a minimum cross-sectional area of approximately:

Accepted Answer

4 mm²

Answer

A minimum 4 mm² cross-sectional area for connectors is recommended to resist fracture under functional occlusal loading.

Question 5

Which design feature of a porcelain-fused-to-metal (PFM) coping helps prevent porcelain fracture at the facial margin?

Accepted Answer

Metal collar or labial shoulder chamfer

Answer

A metal collar or deep chamfer at the facial margin supports the porcelain edge and prevents chipping by eliminating unsupported ceramic.

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