Role of thin gingival phenotype and inadequate keratinized mucosa width (<2 mm) as risk indicators for peri-implantitis and peri-implant mucositis

Background There is growing evidence on the impact of thin gingival phenotype (TnP) and inadequate keratinized mucosa width (KMW <2 mm) around dental implants on peri-implant health. This study investigated the role of TnP and inadequate KMW (<2 mm) as risk indicators for peri-implantitis and mucositis and on dental patient-reported outcomes. Methods Sixty-three patients with 193 implants (mean follow-up of 6.9 +/- 3.7 years) were given a clinical and radiographic examination and a questionnaire to assess patient awareness of food impaction and pain/discomfort. Chi-squared tests and regression analysis for clustered data were used to compare outcomes. Results Implants with TnP had a statistically higher prevalence of peri-implantitis (27.1% versus 11.3%; PR, 3.32; 95% confidence interval (CI), 1.64-6.72; P = 0.001) peri-implant mucositis (42.7% versus 33%; PR, 1.8; 95% CI, 1.12-2.9; P = 0.016) and pain/discomfort during oral hygiene (25% versus 5%; PR, 3.7; 95% CI, 1.06-12.96; P = 0.044) than thick phenotype. Implants with inadequate KMW had a statistically higher prevalence of peri-implantitis (24.1% versus 17%; PR, 1.87; 95% CI, 1.07-3.25; P = 0.027) and peri-implant mucositis (46.6% versus 34.1%; PR, 1.53; 95% CI, 1-2.33; P = 0.05) and pain/discomfort during oral hygiene (28% versus 10%; PR, 2.37; 95% CI, 1.1-5.1; P = 0.027) than the adequate KMW. TnP was strongly associated with inadequate KMW (PR = 3.18; 95% CI, 1.69-6.04; P <0.001). Conclusion TnP and inadequate KMW (<2 mm) may be significant risk indicators for peri-implant disease and pain/discomfort during brushing.