Short implants with a nanometer-sized CaP surface provided with either a platform-switched or platform-matched abutment connection in the posterior region: a randomized clinical trial.

OBJECTIVE To assess the performance of short nanorough implants (8.5 mm in length) provided with either a platform-matched or a platform-switched implant-abutment connection, placed in the resorbed posterior region of partially dentate patients. MATERIALS AND METHODS A total of 149 implants with a dual-acid surface and a discrete crystalline deposition of nanometer-sized CaP particles, with either a platform-matched (control) or a platform-switched implant-abutment connection (test) were placed (randomly assigned) in 92 patients. Follow-up visits were conducted 1 month and 1 year after placing the implant crown. Outcome measures were implant survival, radiographic peri-implant bone loss, clinical parameters, and patient's satisfaction. RESULTS One year after loading, 6 of 76 implants in the control group (survival 92.1%) and 3 of 73 implants in the test group (survival 95.9%) were lost (P = 0.33). Radiographic bone loss around test implants (0.50 ± 0.53 mm) was significantly less than around control implants (0.74 ± 0.61 mm; P < 0.005). With regard to implant survival, clinical parameters, and patient's satisfaction, no significant differences were observed between test and control group. CONCLUSIONS For teeth replacements in the resorbed posterior region of partially dentate patients, short implants with a platform-switched implant-abutment connection showed significantly less peri-implant bone loss after 1 year in function, while implant survival, clinical parameters, and patient's satisfaction were independent of the implant-abutment connection design.