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

Abstract

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.

© 2012 John Wiley & Sons A/S.