Immediate load full-arch mandibular implant-retained FDPs over 3-years RCT

Objectives: Appraise the feasibility of loading four mandibular implants with a fixed dental prosthesis (FDP) same day as the implant placement compared to waiting for four months healing.  Methods: Patients with an edentulous, fully healed mandible were recruited in a faculty graduate clinic to partake in a two-arm parallel blinded randomized controlled trial (RCT). Forty-two patients received 4 implants to support a 10/12-unit FDP. The implants were Replace Select with a Ti-Unite surface (Nobel Biocare AG, Switzerland). In the experimental group the implants were loaded on the same day using the converted pre-existing denture. The patients used this prosthesis for approximately 2 weeks before receiving a permanent FDP.  In the control group the implants were placed using a one-stage surgery procedure and a denture was used until a permanent FDP was fabricated 4 months later. The FDPs were fabricated in a Type-3 cast precious alloy veneered with acrylic and artificial teeth. Patients have been recalled annually for at least 3 years. Results:   Of the original randomized 2x21 patients, five of the patients allocated to the experimental group did not receive allocated intervention, of which 3 were switched from the experimental to the control group. 36 participants returned at the 3 years clinical and radiological examination. The crestal bone level mean changes were identical in the experimental (ITT n=17, PP n=14) and control (ITT/PP n=19) groups: 1.2 (1 yr), 1.7 (2yrs) and 2.2 mm (3 yrs). There was no difference between the experimental and the control group re. frequency of biological and technical complications. Conclusions: Same day loading of implants in the anterior mandible to retain a full arch FDP compared to waiting for four months before loading seems to yield comparable outcomes after 3 years observation. Acknowledgment: This study was made possible by a grant from Nobel Biocare AG, Switzerland.