Impact of platform switching on inter-proximal bone levels around short implants in the posterior region; 1-year results from a randomized clinical trial

Aim To assess the outcome of short implants (8.5 mm) supplied with a conventional platform‐matched implant‐abutment connection or a platform‐switched design. Materials and Methods Eighty patients with one or more missing teeth in the posterior zone were randomly assigned to be treated with implants with either a conventional (control) or a platform‐switched (mismatch 0.35–0.40 mm) implant‐abutment connection (test). Follow‐up visits were conducted 1 month and 1 year after placing the implant crown. Outcome measures were inter‐proximal bone loss, using standardized peri‐apical radiographs, implant survival, clinical parameters and patients' satisfaction. Results One year after loading, inter‐proximal bone loss around test implants (0.51 ± 0.51 mm) was significantly less than around control implants (0.73 ± 0.48 mm) (p = 0.011). Moreover, bone loss was less around 1 versus 2 adjacent implants (p = 0.001), in both the test (0.29 ± 0.36 versus 0.71 ± 0.55 mm) and control (0.46 ± 0.42 versus 0.88 ± 0.45 mm) group. With regard to implant survival, clinical parameters and patients' satisfaction no differences were observed between the test and control group. Conclusion This study suggested that crestal bone resorption may be reduced by platform switching. One year after loading, inter‐proximal bone levels were better maintained at implants restored according to the platform switching concept.