Peri-implant marginal bone level: a systematic review and meta-analysis of studies comparing platform switching versus conventionally restored implants

Aim To systematically review the literature to compare implant survival (IS) and marginal bone loss (MBL) around platform-switched (PS) versus conventionally restored platform-matching dental implants. Material and Methods Randomized, controlled human clinical trials (RCTs) comparing IS and MBL in PS and conventionally restored implants, with 12 similar to months of follow-up and at least 10 implants were identified through electronic and manual search. Review and meta-analysis were performed according to PRISMA statement. Risk ratio (RR) for implant failure and mean difference (MD) for MBL, with 95% confidence interval (CI) were calculated. Sources of heterogeneity among studies were also investigated by subgroup analyses. Results Ten RCTs involving 435 subjects and 993 implants contributed to this review. The cumulative estimated implant success rate revealed no statistically significant difference between the two groups. At a patient level, a smaller amount of MBL [MD -0.55 similar to mm, 95%CI (-0.86; -0.24), p similar to=similar to 0.0006] was noted around PS implants. Subgroup analyses performed at implant level suggested less MBL when platform switching showed a larger mismatching. Conclusion PS technique appeared to be useful in limiting bone resorption. Nevertheless, these data should be interpreted cautiously as significant heterogeneity and possible publication bias were noted. Further research is needed to identify the factors most associated with successful outcomes.