OBJECTIVES: To test the null hypothesis of no difference in the implant failure rates, marginal bone loss (MBL) and postoperative infection in patients who received platform-switched implants or platform-matched implants, against the alternative hypothesis of a difference. DATA: Main search terms used in combination: dental implant, oral implant, platform switch, switched platform, platform mismatch, and dental implant-abutment design. SOURCES: An electronic search without time or language restrictions was undertaken in December/2014 in PubMed/Medline, Web of Science, Cochrane Oral Health Group Trials Register plus hand-searching. STUDY SELECTION: Eligibility criteria included clinical human studies, either randomized or not. CONCLUSIONS: Twenty-eight publications were included, with a total of 1216 platform-switched implants (16 failures; 1.32%) and 1157 platform-matched implants (13 failures; 1.12%). 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). An increase of the mean difference of MBL between the procedures was observed with the increase in the follow-up time (P=0.001) and with the increase of the mismatch between the implant platform and the abutment (P=0.001). Due to lack of satisfactory information, meta-analyses for the outcomes 'implant failure' and 'postoperative infection' were not performed. 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. CLINICAL SIGNIFICANCE: The question whether platform-matched implants are more at risk for failure and loose more marginal bone than platform-switched implants has received increasing attention in the last years. As the philosophies of treatment alter over time, a periodic review of the different concepts is necessary to refine techniques and eliminate unnecessary procedures, forming a basis for optimum treatment.