Platform-Switching Concept in Dental Implants: A Systematic Review and Meta-analysis of Randomized Controlled Trials with a Minimum Follow-up of 3 Years

Purpose: To evaluate studies with a minimum follow-up of 3 years to find the peri-implant marginal bone loss (MBL) and rate of implant failure with platform-switching (PS) and platform-matching (PM) implant-abutment connections. Materials and Methods: A systematic review and meta-analysis was done based on the preferred reporting items for systematic reviews and meta-analyses guidelines, with a focused question on population, intervention, comparison, and outcome. The Cochrane Collaboration's Risk of Bias tool was used to assess bias. Randomized controlled trials (RCTs) comparing peri-implant MBL and implant failure in patients receiving PS implants and PM implants only were included. The risk ratio (RR) of the implant-abutment connection and implant failure was calculated, and peri-implant MBL was expressed in mean differences (MD) at 95% confidence intervals (Cls). Results: Three hundred eighty-one articles were obtained after an initial literature search. Finally, nine articles were included in the study that fulfilled the inclusion criteria. Four hundred twenty-six PS and 411 PM implants were placed with 16 implant failures (8 PS and 8 PM). The implant survival rate was 98.12% for the PS group, and 98.05% for the PM group, with no statistically significant difference (P = .97). The mean peri-implant MBL with the PS implant was lower (0.33 +/- 0.41 mm) compared with the PM implant (0.66 +/- 0.42 mm). A significant effect of PS implants was found in reducing peri-implant MBL (MD:-0.70, 95% CI:-1.25,-0.15; P= .01) compared with PM implants. The MD of peri-implant MBL between the PS and PM implants decreases with increased follow-up: MD of 0.69 (P = .15) with follow-up of z 3 years but < 5 years, and MD of 0.62 (P = .04) with follow-up of z 5 years. Conclusion: Reduced peri-implant MBL was found with the PS concept. The peri-implant MBL decreases with an increased mismatch between the abutment and implant platform. The difference in peri-implant MBL in PS and PM implants in the maxilla was greater and favored the PS concept. Bone-level implants with single crowns or splinted prostheses better preserved the peri-implant marginal bone with the PS concept.