Retrospective analysis of removable partial denture treatment in a state-sponsored dental school

Removable partial dentures (RPDs) provide an important treatment option for replacing missing teeth, particularly for vulnerable populations. However, RPDs have been associated with damage to the remaining dentition, which can lead to treatment failure.

The purpose of this retrospective clinical study was to investigate the failure rates of RPD treatments among patients at a state-sponsored dental school and identify factors contributing to these failures.

A retrospective analysis was conducted using electronic health records (EHRs) from 4941 individuals for a total of 7529 patient-arches. The outcome of RPD treatment was defined as failure when any major procedure was performed on any tooth adjacent to a treated edentulous span. The time to event was measured from the date of RPD placement to the first recorded failure or the last follow-up visit (censored). A multivariable Cox proportional hazards model was employed to assess the hazard ratios for the variables of interest (α=.05).

The average age of the cohort was 59 years, 52% female, and the mean follow-up period was 35 months. Among the arches that experienced failure (24.2%), the average time to failure was 33 months. In the multivariable model, statistically significant associations with RPD failure were found for several variables: Kennedy classification without distal extension (HR=1.23, P<.001), older age (HR=1.01, P<.001), male sex (HR=1.17, P=.008), maxillary arch (HR=1.60, P<.001), lack of insurance (HR=0.78, P<.001), cast metal framework (HR=0.55, P<.001), tobacco use (HR=1.21, P=.002), and dental fear (HR=1.26, P=.003).

While the associations were not particularly strong, dental school patients who smoked, experienced dental anxiety, or received maxillary RPDs or RPDs without a cast metal framework demonstrated an elevated risk of requiring major treatment to the abutment teeth, leading to the failure of the RPD treatment.