Keratinized mucosa width is associated with severity of peri-implant mucositis. A cross-sectional study.

Objectives: This is a cross-sectional study designed with the aim to assess associations between the width of keratinized tissue and peri-implant mucositis.

Materials And Methods: Two hundred and thirty one dental implants in 52 patients were evaluated. The width of keratinized mucosa (KM), plaque index (mPI), gingival index (mGI), bleeding on probing index (BoP), and the probing depth (PD) were measured clinically. Reduced KM was defined as a width of KM below 2 mm and 1 mm, respectively. In the primary analysis, data were analyzed on the implant level with the help of a generalized estimating equations (GEE) model. In sensitivity analyses, an adjusted linear mixed model was performed.

Results: Forty four implants in 12 patients had less than 2 mm KM, and 187 implants in 40 patients had ≥ 2 mm KM. In the non-adjusted analysis on the implant level, reduced keratinized tissue width was significantly associated with peri-implant mucositis (OR 3.3, 95%-CI (1.3-8.0), p = 0.009) and severity of disease (mean difference 2.5, 95%-CI (0.8-4.2) p = 0.004). In sensitivity analyses, reduced keratinized tissue showed a significant association with severity of disease (OR 1.7, 95%-confidence interval = 0.1-34, p = 0.040).

Conclusion: A reduced width of keratinized tissue around dental implants is a risk indicator for severity of peri-implant mucositis. The overall tendency of the results indicates that a sufficient amount of KM may contribute to reduce risk for and severity of peri-implant mucositis.