What is the primary purpose of using a bevel in cavity prep design?

Using a bevel in cavity preparation design primarily serves to reduce stress concentration. The angle created by the beveled edge helps to distribute the occlusal forces more evenly across the tooth structure and the restoration material. This is important because concentrated stress can lead to cracks or failure in both the tooth and the restorative material. By reducing these stress concentrations, the longevity and effectiveness of the restoration are improved, leading to better overall outcomes for the patient.

This technique is especially significant when preparing a cavity for various types of restorative materials. A properly beveled edge allows for a more gradual transition between the different materials and the tooth structure, which further supports the integrity of the restoration over time.