Key points are not available for this paper at this time.
Background The implants, even the bone level ones, have a component that comes into contact with tissues that are not only bone, but epithelial and connective, namely the soft tissues. In recent times, abutments with convergent or concave transmucosal profiles were introduced, this peculiar design as opposed to the classic divergent or parallel ones, in addition to providing the biological width with a more horizontal housing for the peri-implant fibers, would also provide more space for soft tissues. Aim/Hypothesis To systematically review the literature comparing marginal bone loss and pink esthetic score around implants with convergent or concave transmucosal profiles versus divergent or parallel profiles. Material and Methods A PICO question was defined and an electronic search on MEDLINE PubMed and Cochrane Oral Health Group databases were performed. Studies documenting implant transmucosal profiles, either tissue level profiles or abutments, and soft and or hard tissue outcomes were considered eligible. Studies were selected on the base of the inclusion criteria and quality assessments. Meta-analyses with subgroup analysis were performed. Results Five papers fulfilled the inclusion criteria, 4 were eligible for meta-analysis. Significantly less marginal bone loss was found around concave convergent abutment or transmucosal profile group with a mean difference of 0.772 (95% CI, 0.450 to 1.095, P < 0.001). In the subgroups analyses for platform-switching and platform-matching connections a significant effect in favor of concave convergent was detected with a standard difference in means of 1.135 (95% CI, 0.688 to 1.583, P < 0.001) when platform-switching was considered. No significant effects were found for platform-matching connections. Conclusion and Clinical Implications Within the limitations of this review, we can conclude that concave convergent implant transmucosal profiles result in less marginal bone loss. No statistically significant results were obtained for soft tissues-related outcomes and for the platform-matching connection subgroup. Implant abutments with a convergent profile or tissue level implants with a narrowing transmucosal component might represent a viable an effective option to improve peri-implant bone related parameters.
Valente et al. (Sun,) studied this question.