A randomised controlled trial of two-unit cantilevered or three-unit fixed-movable resin-bonded fixed partial dentures replacing missing molars

Objective: : To examine the short-term clinical performance and patient-reported outcomes of two-unit canti-levered (CL2) and three-unit fixed-movable (FM3) RBFPDs for replacement of single molar-sized spans.Materials and Methods: : Subjects with an 8-10 mm molar-sized edentulous span(s) and 12 pairs of occluding units were randomly assigned to receive either CL2 or FM3 RBFPD (ratio 1:1). The survival (retention of original prosthesis) and success (survival, complication-free) of RBFPDs at one-year were analysed. Patient-reported outcomes were assessed by prosthesis satisfactory questionnaire and Oral Health Impact Profile (OHIP-49). Data in mean, proportion and longevity were analysed by t-test/Mann-Whitney U test/Wilcoxon signed-rank test, chi-square and log-rank tests respectively at significance level alpha = 0.05. Trial registration: ClinicalTrials.gov Identifier NCT02239718.Results: : Ninety-eight RBFPDs (42 CL2 and 56 FM3) were delivered in eighty-three patients. Majority (n = 89) of the prostheses were provided by operators who have less than 2 years of clinical experience. Sixty-six patients with seventy-eight RBFPDs (35 CL2 and 43 FM3) were reviewed at one-year. One CL2 and one FM3 RBFPDs debonded, resulting in a success rate at 97.1 % and 97.7 % respectively (P > 0.05). Both RBFPDs were rebonded and the survival rate were 100 % for both designs. No significant difference in satisfactions and summary OHIP-49 scores were observed (P > 0.05).Conclusion: : CL2 RBFPDs can be used for replacing molar-sized edentulous spans with minimal observable complications up to one-year. Longer-term data is being collected.Clinical significance: : This clinical trial demonstrates CL2 RBFPDs have comparable clinical and patient-reported outcomes as the FM3 design. This challenges the current dogma in prosthodontics and expands the clinical use of CL2 design which is more conservative, simpler and easier for patients to maintain.