What is a sign that the RPD base is not accurately adapted to the soft tissue?

A visible pressure mark from the base of a removable partial denture (RPD) is a clear indication that the base is not accurately adapted to the soft tissue. These pressure marks result from areas where the denture base is either too high or does not fit snugly against the underlying tissues, leading to localized pressure. When an RPD does not conform well to the soft tissue, it can cause irritation and discomfort, which manifests as red or sore spots on the gums.

In contrast, rigidity of the base suggests it is well-constructed, while an absence of movement during placement indicates a good fit and retention. Immediate comfort upon placement typically signifies that the denture is correctly designed and fits the anatomy of the mouth well. Therefore, visible pressure marks are direct evidence of poor adaptation, highlighting the need for adjustments to achieve a better fit and enhance patient comfort.