What is one of the functions of vertical stops in rest seats?

Vertical stops in rest seats primarily serve to direct forces down the long axis of the tooth during function. This is essential for the stability and longevity of the removable partial denture (RPD) because when occlusal forces are applied, they should ideally be transmitted directly along the long axis of the abutment teeth. This alignment minimizes the risk of tooth movement or damage that can occur if forces are applied at an angle. By ensuring proper force distribution, vertical stops help to maintain the integrity of both the partial denture and the supporting teeth over time. This function is foundational in the design of RPDs, as it significantly impacts the overall effectiveness and comfort of the dental prosthesis during use.