Evaluation of the effect of keratinized mucosa on peri-implant tissue health using a multivariate analysis

Purpose: This study investigated the relationship between peri-implant tissue health and the presence of keratinized mucosa (>= 2 mm) using multivariate analysis. Methods: A total of 334 dental implants placed in 111 partially edentulous patients (34 males, 77 females) and restored with fixed prostheses were included in this study. The patients were recalled 12-146 months after completion of the prosthodontic treatment. Clinical parameters included modified plaque index (mPI), modified bleeding index (mBI), probing pocket depth (PPD), and radiographic bone loss (BL). The effects of the following potential explanatory variables on these parameters were analyzed: the presence of keratinized mucosa, age. sex, oral hygiene status, history of periodontitis, cigarette smoking. implant site, and time elapsed since prosthesis delivery. Statistical analysis included multivariate ordinal logistic regression and generalized estimating equations. Significance was established when two-sided p-values were less than 0.05. Results: The mPI, mBI, and PPD in the presence or absence of keratinized mucosa did not show statistically significant differences. However, the presence of keratinized mucosa was significantly related to BL (odds ratio 4.33, p < 0.01). Conclusions: The results of our study suggest that the presence of keratinized mucosa is useful for reducing bone resorption and can help to maintain per-implant tissue health