Which factor may limit the effectiveness of an RPD in a patient?

Severe residual ridge resorption significantly impacts the effectiveness of a removable partial denture (RPD). When there is substantial resorption of the jawbone where teeth have been lost, the supportive structure for the denture decreases. This can lead to issues such as instability, discomfort, and difficulty in achieving proper retention for the RPD. The lack of adequate ridge height and width may compromise the fit and function of the denture, making it harder for the patient to chew comfortably and potentially affecting speech.

In contrast, factors like high dental insurance coverage, regular dental check-ups, and good oral hygiene practices generally enhance the patient's overall dental health and support successful denture use. These factors contribute to better maintenance and management of oral health, which can help in prolonging the life and functionality of an RPD but do not directly address structural limitations caused by resorption of the ridge.