Occlusal Veneers and Load-Bearing Capacity of a Restored Tooth.

This article investigates the effects of restoration bonding and preparation design on the load-bearing capacity of human molar teeth restored with indirect occlusal veneers made from lithium-disilicate glass-ceramic (LDGC) or hybrid-ceramic (HC) materials. Using extracted molars prepared with or without a circumferential chamfer, veneers were bonded either according to manufacturers' instructions or with intentionally deteriorated bonding via n-hexane wax preconditioning. Results showed that teeth restored with bonded LDGC veneers exhibited significantly higher fracture loads, exceeding the fracture resistance of tooth structure, while bonded HC veneers provided only marginal improvement over nonbonded restorations. Chamfer preparation did not significantly influence fracture resistance under vertical loading, and in nonbonded groups, veneers loosened without tooth fracture regardless of material. The study highlights the critical role of adhesive bonding quality and material selection, particularly favoring LDGC veneers, in enhancing the mechanical durability of occlusal veneer restorations.