Where should occlusal load be distributed in an all-ceramic restoration?

In an all-ceramic restoration, occlusal load should ideally be distributed in the area where porcelain is supported by enamel. This is because enamel is significantly stronger and has better fracture resistance than dentin, making it the most suitable substrate for load-bearing in ceramic applications. When the porcelain is in contact with enamel, it is less likely to experience chipping or fracture, as the surface maintains a better bond and the mechanical properties between the two materials are optimized. This placement helps ensure the longevity and durability of the restoration, preventing potential failures that may arise from inappropriate load distribution.

Moreover, distributing the occlusal load in areas supported by dentin, or other less stable regions, can lead to an increased risk of restoration failure due to the inherent properties of dentin, which does not provide the same level of support as enamel. This ultimately emphasizes the importance of ensuring that the design and placement of all-ceramic restorations are focused on maximizing support and minimizing risk.