When inlays rely on cusps bulk, what may this lead to?

When inlays rely on the bulk of the cusps, this approach can lead to the fracture of cusps. This occurs because the natural tooth structure is not designed to bear the added occlusal forces concentrated on the cusps due to the inlay. If the inlay does not fully support the surrounding tooth structure or if it's designed in such a way that it places undue stress on the cusps, the risk of mechanical failure increases. Cusp fractures can occur not only from excessive occlusal load but also from the inherent weaknesses that may exist in the remaining tooth structure, especially if it's already compromised by decay or previous restorations.

Understanding this relationship emphasizes the importance of preserving as much tooth structure as possible while ensuring that inlays are designed and placed in a manner that distributes forces evenly across the tooth. When cusps are inadequately supported, restoration longevity and overall tooth health can be jeopardized.