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.