What is the minimum occlusal reduction required for a porcelain-fused-to-metal (PFM) crown?

For a porcelain-fused-to-metal (PFM) crown, the minimum occlusal reduction typically required is 1.5mm. This amount of reduction is crucial because it allows for sufficient space to accommodate the metal substructure and the ceramic material that will be layered on top.

The metal substructure provides strength and support, while the porcelain layer gives the crown its aesthetic appearance. If the reduction is less than the recommended 1.5mm, there may not be enough volume to create a durable crown that withstands the occlusal forces encountered during chewing. Adequate reduction ensures proper contours and helps to maintain the longevity of the crown, as well as preventing issues related to over-contoured restorations, which can affect the bite and lead to discomfort or dysfunction.

In comparison to the other options, a 2.0mm or 2.5mm reduction may provide ample space, but it is often more than necessary and could compromise the health of the remaining tooth structure. Similarly, a reduction of 1.0mm would be insufficient for PFM crowns, potentially leading to complications in both aesthetics and functionality. Thus, the 1.5mm reduction strikes the right balance for optimal crown fabrication.