Which condition indicates the need for a functional reline at the RPD placement appointment?

A functional reline is necessary when the removable partial denture (RPD) exhibits undesirable movements under occlusal forces. Specifically, if simulated occlusal forces cause movement of rests or the lingual plate, it indicates that the fit of the RPD is compromised. This movement signifies that the supporting structures, such as the soft tissues or residual ridge, may not provide adequate stability or support for the prosthesis, which ultimately can lead to discomfort, functional inefficiency, and potential damage to both the RPD and the residual tissues.

In contrast, while excessive lateral movement and visible cracks in the denture base can point to issues with the RPD, they do not directly indicate the need for an immediate functional reline at the placement appointment in the same context that the movement of rests and lingual plates does. Excessive lateral movement might suggest poor fit, but it is the functional response under occlusal forces that truly dictates the need for re-evaluation and adjustment. Wear of artificial teeth, while a sign of age and use, does not indicate an immediate need for a functional reline as it pertains more to aesthetics and occlusion rather than the fundamental fit or function of the RPD itself at the moment of placement.