Retrospective Study of the Association between Peri-Implantitis and Keratinized Mucosa

1. Background: Peri-implantitis affects a high percentage of patients treated with dental implants. Among the risk factors that can cause this pathology, limited evidence exists regarding the absence of keratinized mucosa. The main objective of this study was to compare the amount of keratinized mucosa around healthy implants versus implants in patients with peri-implantitis, in order to analyze its influence on esthetics and the development of this pathology, and to study the possible influence of keratinized mucosa on various clinical parameters. 2. Methods: A retrospective case-control study was carried out in which 203 implants were evaluated, 103 of which presented a healthy peri-implant state, versus 100 which had peri-implantitis. The following elements were recorded: keratinized mucosa, recession, plaque index, bleeding, suppuration, probing depth, and bone level. 3. Results: Keratinized mucosa was present in 51% of the peri-implantitis group versus 97.1% of the healthy implants. In implants without keratinized mucosa, both recession and plaque index, bleeding on probing (96.2%), suppuration (57.7%), mean probing depth and bone level were higher. Implants without keratinized mucosa presented worse esthetics. 4. Conclusions: Absence of Keratinized mucosa around dental implants seems to be associated with the appearance of peri-implantitis modifying certain clinical parameters: there is a greater probability of recession, bleeding, suppuration, deficient hygiene, greater probing depth and greater bone loss in implants without keratinized mucosa.