Non-surgical treatment of peri-implantitis with submarginal erythritol air-polishing in severe periodontitis patients: a randomized controlled trial.

AIM: To evaluate the clinical and radiographic outcomes of non-surgical treatment by either submarginal erythritol air-polishing or combined instrumentation for peri-implantitis in severe periodontitis patients. MATERIALS AND METHODS: This randomized clinical trial enrolled patients diagnosed with stage III/IV periodontitis and peri-implantitis affecting at least one dental implant. The test group received erythritol air-polishing while the control group received ultrasonic combined with manual instrumentation for peri-implant submarginal debridement. The primary outcome was the mean peri-implant probing depth (PPD) at 3 months. Clinical parameters were assessed at baseline (T0), T1 (6 weeks), and T2 (3 months); radiographic parameters were assessed at T0 and T2. Intergroup differences were analyzed using the Mann-Whitney U or t-test at each timepoint and verified by mixed-effects models. Factors potentially influencing PPD prognosis were assessed using Generalized Estimating Equations (GEE). RESULTS: Initially, 40 patients (20 per group) with peri-implantitis were randomly assigned to the trial; 38 patients completed the study. At T2, mean PPD reduced from 6.0 ± 1.8 mm to 4.2 ± 1.6 mm (test group) and 4.7 ± 1.5 mm (control group) with no significant differences between groups. Mean modified sulcus bleeding index(mSBI) decreased in both groups, with a significantly greater reduction in the test group. The treatment efficacy of PPD can be influenced by keratinized mucosa width (KMW), PPD-T0, mSBI-T2, and probing depth reduction of adjacent teeth. CONCLUSIONS: In patients with severe periodontitis, both non-surgical therapies were effective in improving clinical parameters of peri-implantitis. Erythritol air-polishing exhibited greater improvement in soft tissue inflammation. Adequate peri-implant keratinized mucosa and greater reduction in probing depth of adjacent teeth were identified as favorable prognostic factors for PPD. CLINICAL TRIAL REGISTRATION: This study had retrospectively registered at Chinese Clinical Trial Registry (ChiCTR2100048446) on July 7, 2021 ( https://www.chictr.org.cn/showproj.html? proj=129220 ).