An RCT Comparing Molar Two-and Three-unit RBBs

Abstract

Objectives: Cantilevered two-unit (CL2), resin-bonded bridges (RBBs) are durable and successful prostheses for missing anterior and premolar teeth. However, the use of CL2 designs for molar-sized edentulous spans goes against previous principles of prosthodontic bridge design. These results update interim findings of a randomized-controlled trial (Clinicaltrial.gov NCT02239718) comparing RBBs of FM3 and CL2 designs for missing molar-sized spans (8-10 mm). Methods: Patients who had one or more missing molar spans that met the inclusion/extrusion criteria (IRB: UW14-233) were recruited and randomized (ratio 1:1) into CL2 or FM3 group. Patients were examined by independent assessors at different time intervals baseline, 1-, 6-, 12- and 24-month after cementation. Retention of the prosthesis was evaluated as well as patient’s satisfaction and oral health-related quality of life were evaluated by 14-item questionnaire and OHIP-49 respectively. Results: Seventy-six patients were enrolled and ninety-five RBBs were randomized into forty-five CL2 and fifty FM3 designs. Sixty seven patients were reviewed at 1-month, thirty-five at 6-months, 30 at 12-month and 10 at 24-months. The majority of the prostheses were provided by undergraduate dental students. Two CL2 and one FM3 RBBs debonded resulting in retention rate of 95.6% and 98.0%. They were all rebonded. Patient reported outcome evaluations and OHIP were analysed by t-test for the two groups and no differences were observed (P> 0.05) and no adverse outcomes were reported such as tipping or discomfort. Conclusions: The most recent data of this study show that CL2 RBBs can be successfully placed for single molar spans with no observable complications. Longer term data is being collected.