Clinical Assessment of Distal Versus Mesial Single-Retainer Resin Bonded Fixed Partial Denture for Replacement of an Upper Lateral Incisor: Randomized Clinical Trial

PURPOSE: To compare 1-year survival rates of zirconia single-retainer resin-bonded fixed partial dentures (RBFPDs) on maxillary canines vs central incisors. MATERIALS AND METHODS: A total of 54 multilayered, ultratranslucent zirconia single-retainer RBFPDs were placed in 50 patients, divided equally into two groups: an intervention group with a distal retainer (D-retainer) on the maxillary canine, and a control group with a mesial retainer (M-retainer) on the maxillary central incisor. Patients were followed up for 1 year. Survival was assessed by debonding, fracture, and abutment mobility using modified USPHS criteria. Patient satisfaction was measured via the visual analog scale (VAS). Fisher exact test was used for comparisons, and survival analysis was performed with the Kaplan-Meier method (significance set at P ≤ .05). RESULTS: The D-retainer group showed an 81% survival rate, with five cases experiencing two debondings. The M-retainer group had an 86% survival rate, with three cases debonding twice. Both groups showed high patient satisfaction and stable abutment mobility. CONCLUSIONS: Within the limitations of this study, no difference was found between canine and central incisor abutments. Both designs showed excellent fracture resistance, stable mobility, and high satisfaction. Debonding was the only failure mode.