Impact of periodontal inflamed surface area on peri-implant mucositis: a retrospective cohort study

To evaluate the association of periodontal inflamed surface area (PISA) and pan-immune-inflammation value (PIV) on the hazard of peri-implant mucositis in patients with severe periodontitis. This retrospective cohort study included implants in patients with severe periodontitis, classified as peri-implant health or mucositis based on clinical and radiographic assessments. Time to first occurrence of peri-implant mucositis characterized by bleeding on probing (BOP) during follow-up of up to 5 years served as the primary endpoint. Cox regression adjusted for patient clustering was performed to examine associations of PISA 0 , PISA 1 , and PIV 0 with this outcome. Secondary exploratory analyses involved restricted cubic spline (RCS) analysis, maximum log-rank threshold determination, and subgroup stratification. A total of 93 partially edentulous patients with 205 implants were included. Multivariate analysis identified PISA 1 , but not PISA 0 , as an independent predictor. A higher PISA 1 exceeding the threshold of 447.8 mm 2 identified high-risk implants, which exhibited a 3.29-fold greater hazard of mucositis ( P < 0.001). High PISA 1 remained associated with a greater hazard in both low and high PIV 0 ( P < 0.05), whereas interaction tests for age, gender, and PIV 0 were not significant ( P > 0.05). Preoperative PISA, but not initial PISA, was associated with peri-implant mucositis. PISA may help quantify residual periodontal inflammatory burden before implant placement. However, the proposed threshold of 447.8 mm 2 and PIV-related findings require further external validation.