What is the optimum cavosurface angle for an occlusal amalgam surface?

The optimum cavosurface angle for an occlusal amalgam surface is typically in the range of 95-110°. This angle is critical for ensuring proper marginal integrity and strength of the restorative material. A wider angle provides a more favorable relationship between the enamel and the amalgam, allowing for adequate retention and minimizing the risk of microleakage.

In addition, a cavosurface angle within this range helps in distributing forces evenly during chewing, which is essential for the longevity of the restoration. It prevents stress concentration at the margins of the amalgam, contributing to a more durable bond with the tooth structure.

Other ranges suggested by the other options do not provide the same level of stability and retention as the wider angle. For example, angles below 90° may lead to undercuts that can compromise the integrity of the restoration, resulting in higher chances of failures or fractures over time.