For gold inlays gingival margin finish line should be
**Core Concept**
In restorative dentistry, the gingival margin finish line is a critical aspect of designing and placing gold inlays. The finish line refers to the area where the inlay meets the tooth structure, and it must be carefully planned to ensure proper marginal fit, prevent leakage, and maintain periodontal health.
**Why the Correct Answer is Right**
The correct answer is **A. Chamfer**. A chamfer finish line is a bevelled angle that follows the curvature of the tooth, creating a smooth transition between the inlay and the tooth. This design helps to reduce the risk of marginal leakage and promotes easier removal of the inlay during future restorative procedures. A chamfer finish line also helps to minimize the risk of periodontal disease by reducing the amount of tooth structure that is removed and by allowing for easier access for oral hygiene.
**Why Each Wrong Option is Incorrect**
* **Option B:** A shoulder finish line is a straight line that follows the curvature of the tooth, which can lead to marginal leakage and make it more difficult to remove the inlay during future restorative procedures.
* **Option C:** A shoulder finish line with a bevel is still a straight line, and the addition of a bevel does not address the issue of marginal leakage.
* **Option D:** A shoulder finish line with a chamfer is redundant and unnecessary, as a chamfer finish line is a more efficient and effective design.
**Clinical Pearl / High-Yield Fact**
When designing a gold inlay, it's essential to consider the gingival margin finish line to ensure proper marginal fit and prevent leakage. A chamfer finish line is generally the preferred design, as it reduces the risk of marginal leakage and promotes easier removal of the inlay during future restorative procedures.
**Correct Answer: A. Chamfer**