Abstract: Objective To investigate the correlation between periodontitis and peri-implant mucositis (PM) under different conditions of plaque control, and to evaluate related risk factors of peri-implant mucositis. Methods Patients who underwent implant surgery at SATH Hospital of stomatology, Henan University from January 2010 to January 2020 and met the the inclusion criteria were randomly recalled. Oral clinical examination and radiographic examination were carried out. The stage and grade of periodontitis, implant plaque index, peri-implant mucositis and so on were recorded. Chi-square test was used to analyze the correlation between periodontitis and PM under different conditions of plaque control, and Logistic regression was used to analyze the indipendent risk factors of PM. Results A total of 182 patients with 427 implants were included in the study. 76（41.8%） patients and 152（35.6%）implants had PM. Regression analysis showed that patients with severe periodontitis（periodontitis ≥ Stage III）（P=0.049,OR=2.108,95%CI: 1.003~4.429）and plaque index (PLI）≥2（P=0.001,OR=3.126,95%CI: 1.566~6.238）had a higher risk of PM. When PLI<2, there was no significant relationship between PM and severe periodontitis（P=0.645）; When PLI≥2, PM was significantly correlated with severe periodontitis（P=0.001）. Conclusion When peri-implant plaque was well controlled, the relationship between periodontitis and PM was not significant. Severe periodontitis was significantly associated with PM when peri-implant plaque control was poor, Therefore, mastering plaque control methods and maintaining periodontal health are of great significance in the prevention of PM.

Key words: Peri-implant mucositis, Peri-implant disease, Periodontitis, Plaque, Implant