Nonprecious Alloy vs Precious Alloy Telescopic Crown-Retained Removable Partial Dentures: Survival and Maintenance Needs

Purpose: The purpose of this retrospective clinical study was to evaluate the clinical outcomes of nonprecious alloy (NPA) vs precious alloy (PA) telescopic crown-retained removable partial dentures (TRPDs), the factors influencing survival, and the type and number of maintenance procedures required during the observation period. Materials and Methods: This retrospective clinical study is based on 462 patients with a total of 572 TRPDs on a total of 1,946 abutment teeth. The following parameters were analyzed with Kaplan-Meier analysis: sex; alloy type: denture location; number and distribution of abutment teeth (Kennedy Class): vitality of abutment teeth; dentition in the opposing arch; and participation in follow-up visits. Results: The mean observation period was 3.87 +/- 3.15 years (2.99 +/- 2.52 years for NPA-TRPDs and 5.36 +/- 3.53 years for PA-TRPDs; maximum 11.01 years). During the observation period, 4.2% (n = 24) of the TRPDs ceased functioning and 8.3% (n = 161) of the abutment teeth had to be removed. The calculated 5- to 10-year survival probabilities were 96.1% and 84.0%, respectively, for the TRPDs. The number of abutment teeth was the only parameter that significantly (P < .05) impacted this probability, whereas the vitality of the abutment teeth and the type of alloy significantly (P < .05) impacted the survival probability of the abutment teeth. NPA-TRPDs needed significantly earlier initial treatment than PA-TRPDs (P < .05). Conclusion: The type of alloy seems to have no impact on TRPD survival, but seems to have an influence on the survival of the abutment teeth. There are also differences in maintenance between NPA- and PA-TRPDs.