Data sources: PubMed/Medline, Web of Science and the Cochrane Oral Health Group Trials Register, clinicaltrials.gov, www.centerwatch.com/clinical-trials, www.clinicalconnection.com supplemented by a manual search of dental implants-related journals.

Study selection: Clinical studies, either randomised or not, comparing implant failure rates, marginal bone level (MBL) and/or postoperative infection in any group of patients receiving platform-switched implants or platform-matched implants were considered.

Data extraction and synthesis: Study quality was assessed using the Newcastle-Ottawa scale (NOS).Only randomised clinical trials (RCTs) were considered for meta-analysis. Implant failure and postoperative infection were the dichotomous outcomes measures evaluated. Weighted mean differences were used for MBL.

Results: Twenty-eight studies (18 RCTs, six CCTs and four retrospective analyses) were included. Twenty-six studies were considered to be of high quality. Twelve hundred and sixteen platform-switched implants were included with 16 failures (1.32%) and 1157 platform-matched implants and 13 failures (1.12%). Twenty studies had no implant failures. In a meta-analysis for the outcome MBL (18-RCTs) there was less MBL loss at implants with platform-switching than at implants with platform-matching (mean difference -0.29, 95% CI −0.38 to −0.19; P<0.00001)

Conclusions: The results of the present study suggest that there is a significantly less MBL loss at implants with platform-switching than on implants with platform-matching. The results of the present review should be interpreted with caution due to the presence of uncontrolled confounding factors in the included studies, most of them with short follow-up periods.