Objectives: Due to the scarce amount of data available, a retrospective analysis of patients treated with removable dental prostheses (RDPs) was performed. The aim of the trial was to evaluate the rate of repairs and failures of attachment-retained RDPs (AR-RDPs) compared to clasp-retained RDPs (CR-RDPs) with respect to cofactors (e.g., type of loading). In this respect, two hypotheses were proposed: AR-RDPs are more prone to repairs than CR-RDPs, and AR-RDPs are more prone to fail than CR-RDPs.
Materials and method: Two hundred three patients treated with 135 AR-RDPs and 68 CR-RDPs between 1994 and 2006 were evaluated in this trial. The dental treatment was carried out in the clinical training course of senior students. Kaplan-Meier estimates were calculated for the primary end point (repairs) and for the secondary end point (failures).
Results: The survival of CR-RDPs and AR-RDPs did show significant differences regarding repairs (p = 0.034) but not with regard to failures (p = 0.169). Prostheses of the non-axially loaded group showed no significant differences in the frequency of repairs and failures.
Conclusions: Technical complications occurred more frequently in the CR-RDP group. Taking the higher observation time in the AR-RDP group into account, CR-RDPs are more prone to repairs, especially to those with technical background (e.g., fracture of the metal framework).
Clinical relevance: The use of crowns with rod attachments on tilted teeth seems to be an appropriate treatment approach in order to simplify removable dental prosthesis design.