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


  • Conflict of interest and source of funding

    The authors declare that they have no conflict of interests or source of funding.


Susanna Annibali

Department of Oral and Maxillofacial Sciences

“Sapienza” University of Rome

6, Caserta St., 00161 Rome





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 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.


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 mm, 95%CI (−0.86; −0.24), p = 0.0006] was noted around PS implants. Subgroup analyses performed at implant level suggested less MBL when platform switching showed a larger mismatching.


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.