Significance of keratinized mucosa/gingiva on peri‐implant and adjacent periodontal conditions in erratic maintenance compliers

Abstract Background Given the fact that most patients are not regular compliers in supportive peri‐implant maintenance programs, it is of interest to examine the significance of the peri‐implant soft tissue characteristics in relationship to the onset of peri‐implant diseases. Methods Based on an a priori statistical power calculation, a cross‐sectional study was conducted on erratic peri‐implant maintenance compliers (<2 times/year) to examine the significance of keratinized mucosa (KM) and gingival tissue (KT) on peri‐implant and adjacent periodontal conditions in implants restored ≥3 years. Seven clinical parameters were recorded around implants and the adjacent buccal sites. Radiographic assessment was performed using periapical X‐rays. In addition, a visual analog scale (VAS) was used to evaluate the impact of KM upon brushing comfort. The case definition used for peri‐implant diseases was in accordance with the 2017 World Workshop on the classification of periodontal and peri‐implant diseases and conditions. Results Overall, 37 patients with 45 edentulous gaps restored with 66 implants and 90 adjacent teeth were analyzed. On comparing a KM band of <2 mm versus ≥2 mm, with the exception of suppuration ( P = 0.6), all the clinical and radiographic parameters were significantly increased when the KM band was <2 mm ( P < 0.001). A significant correlation was observed between KM and KT (r = 0.55), though a lack of KM did not condition a lack of KT. In the presence of peri‐implantitis, only bleeding on probing at the adjacent dentate sites was identified to be increased. Conclusions The presence of <2 mm of KM around dental implants in erratic maintenance compliers seems to be associated with peri‐implant diseases. The lack of KM constitutes a site‐specific phenomenon independent of the keratinized tissue present in the adjacent dentition (NCT03501537).