What is the primary role of the occlusal rest in an RPD?

The primary role of the occlusal rest in a removable partial denture (RPD) is to provide vertical support and prevent movement of the prosthesis during function. The occlusal rest is specifically designed to fit into the prepared rest seat on the natural tooth, allowing it to distribute occlusal forces appropriately. This placement helps to stabilize the RPD, maintaining its position and preventing rocking or dislodgment during activities such as chewing or speaking.

By providing vertical support, the occlusal rest also helps transfer some functional forces to the natural dentition, which can enhance the overall effectiveness of the RPD and improve patient comfort. This support is essential in ensuring the longevity and functionality of the prosthesis, as it directly contributes to the overall fit and usability of the RPD in the oral cavity.