What is the minimum labial reduction recommended for a PFM preparation?

The minimum labial reduction recommended for a porcelain-fused-to-metal (PFM) preparation is 1.5 mm. This amount of reduction is significant for several reasons. First, it ensures adequate space for the metal substructure, which is essential for the strength and durability of the restoration. Insufficient reduction could lead to a lack of support for the porcelain, resulting in potential fractures or chipping of the tooth structure.

Additionally, a reduction of 1.5 mm allows for a sufficient thickness of the porcelain on the labial surface, ensuring optimal esthetics and adequate light transmission through the restoration. This thickness helps in mimicking the natural tooth's translucency and color characteristics, making the final restoration more lifelike.

In contrast, options with lesser reductions, like 1.0 mm or 0.5 mm, do not provide enough material thickness for strength and aesthetics, while an option of 2.0 mm exceeds the minimum needed, which might lead to unnecessary loss of tooth structure. Therefore, 1.5 mm is the optimal amount, balancing both structural integrity and aesthetic appearance for PFM preparations.