Influence of keratinized mucosa on the surgical therapeutical outcomes of peri-implantitis

Aim: To assess the impact of keratinized mucosa (KM) width around dental implants on surgical therapeutic outcomes when treating peri-implantitis. Material and Methods: Surgically treated peri-implantitis implants were divided into two groups (KM width < 2 mm and ≥2 mm). Retrospective data were obtained after implant placement (T0) and the day of peri-implantitis surgical treatment (T1). Patients were later recruited (≥1 year after T1) for clinical and radiographic examination (T2). Outcomes were analysed using generalized estimating equation (GEE) models. Results: A total of 40 patients (68 implants) (average follow-up: 52.4 ± 30.5 months) were included in this study. From T0 to T1, no differences were found between KM groups in terms of peri-implant probing depths (PPD) and bleeding on probing (BOP). However, sites with <2 mm KM exhibited significantly higher suppuration (SUP) and lower marginal bone level (MBL) (p >.01). Between T1 and T2, no major differences were noted on PPD reduction, BOP and MBL changes between the two groups. GEE modelling demonstrated that MBL severity prior to surgical therapy was a better predictor for implant survival than KM width. Conclusion: Surgical outcome in treating peri-implantitis was influenced by the severity of bone loss present at the time of treatment and not by the presence of KM at the time of treatment.