Marginal Fit And Cementation Of A Crown

Question 1

Subgingival crown margins justified for the following reasons?

Answer 1

1. Subgingival caries
2. Extension of the preparation margins on sound tooth structure beyond existing restorative materials or abrasion
3. To increase resistance and retention form for short clinical crowns
4. For aesthetics.

Question 2

What can inadequate marginal fit of a restoration lead to?

Answer 2

Plaque accumulation increasing the risk of caries, microleakage and endodontic inflammation, periodontal diseases, cement dissolution

Question 3

Primary function of cementation?

Answer 3

1. Establish reliable retention
2. Durable seal of the space between the restoration and the tooth
3. Provide adequate optical properties