onlay restoration:
- A. larger than amalgam restoration CORRECT ANSWER-AMEL
- B. smaller than amalgam
- C. same as amalgam
- D. depend on caries extension ***
The correct answer is A. larger than an amalgam restoration.
Onlay restorations are typically larger than amalgam restorations for several reasons:
- Function:
Onlays are often needed for teeth with significant structural damage caused by decay, fractures, or large fillings. They cover more tooth surface compared to amalgam fillings, providing additional support and protection.
- Material properties:
Onlay materials like porcelain or composite resin usually require a thicker layer for adequate strength and durability compared to amalgam.
- Preparation:
Onlay preparation involves removing more tooth structure to create a stable and retentive surface for the restoration. This results in a larger restoration compared to an amalgam filling.
While the exact size of an onlay can vary depending on the specific case and extent of damage, it will usually be larger than an amalgam restoration used for a smaller cavity.
Therefore, option D, "depends on caries extension," is partially correct. While the caries extension does influence the size of both restorations, in most cases, onlays will be larger due to their functional and material limitations.
