April 2021

Aims: To investigate the association between the keratinized mucosa (KM) width and peri-implant diagnostic parameters in implant maintenance. Methods: A total of 331 posterior implant-supported fixed prostheses in 165 patients were evaluated. Demographic data were collected from history taking and treatment records. Plaque index, bleeding index, probing depth, mucosal recession, and bone level in relation to buccal keratinized mucosa were examined. The Kruskal-Wallis, Mann-Whitney U, and multivariable models were used as the statistical tests. Results: The majority of subjects attended implant maintenance at least once a year and demonstrated optimal oral hygiene. keratinized mucosa width ranged from 0–7 mm. Considering the keratinized mucosa widths, a marked recession was determined at < 2 mm keratinized mucosa and less recession was determined at > 2 mm keratinized mucosa. The multivariate model indicated that < 2 mm keratinized mucosa was significantly associated with increased mucosal recession (B = 0.12; CI: 0.01, 0.23). Plaque accumulation, mucosal inflammation, and interproximal bone level were not related to keratinized mucosa width after adjusting for oral hygiene, smoking status, history of chronic periodontitis, and implant prosthesis type. Conclusion: The presence of < 2 mm of KM width was associated with mucosal recession. However, other peri-implant diagnostic parameters were not associated with the width of keratinized mucosa.