The relationship between adequate keratinized mucosa and peri-implant disease: a systematic review and meta-analysis.

Background: Controversial conclusions have been drawn from recent researches that examined the impact of keratinized mucosa width on clinical parameters of peri-implant health status. The purpose of this meta-analysis is to assess the effect of keratinized mucosa width on these clinical parameters by combining data from different studies.

Methods: A systematic literature search was performed using PubMed, Web of Science, China National Knowledge Infrastructure (CNKI), and VIP Data from the beginning of the database until May 2024. Mean difference (MD) along with the 95% confidence interval (CI) were calculated for plaque index (PI), gingival index (GI), bleeding index (BI), probing depth (PD), clinical attachment level (CAL) and bone loss (BL). The Q test and I statistic were used to determine heterogeneity. Publication bias was evaluated by Begg's test and Egger's test.

Results: A total of 30 articles were included for meta-analysis. Implants with adequate width of keratinized mucosa (≥ 2 mm) presented significantly reduced PI (MD: -0.30, 95% CI: -0.42 to -0.17), GI (MD: -0.26, 95% CI: -0.38 to -0.13), BI (MD: -0.20, 95% CI: -0.33 to -0.07), and BL (MD: -0.27, 95% CI: -0.42 to -0.12). Although significant heterogeneity was detected among the included studies, sensitivity analysis further demonstrated the robustness of the results.

Conclusions: The meta-analysis demonstrated that adequate width of keratinised mucosa (≥ 2 mm) around dental implants is associated with reduced plaque accumulation, tissue inflammation, and bone loss.