Which type of dental restoration is most likely to result in cusp fractures?

Large posterior restorations are most likely to result in cusp fractures due to several factors intrinsic to their location and size. Posterior teeth, particularly molars, are subject to significant occlusal forces during chewing and grinding. When a restoration occupies a large volume of a tooth, it can compromise the structural integrity of the remaining tooth structure, particularly the cusps.

In larger restorations, the amount of tooth structure retained is reduced, diminishing the ability of the tooth to withstand the forces exerted during function. This reduced strength can lead to increased stress concentrations at the cusps, especially where the restorative material interfaces with natural tooth structure. If these stresses exceed the fracture resistance of the tooth, cusp fractures may occur.

Additionally, the materials used in large posterior restorations can have different mechanical properties compared to natural tooth structure. If these materials are not properly bonded or if they shrink during curing, it can create additional stress points that further increase the likelihood of fractures.