Abstract: PURPOSE: To investigate the therapeutic effect of Xipayi Guyin fluid combined with metronidazole in treating periimplantitis and its impact on the levels of matrix metalloproteinase 8 (MMP-8) and nitric oxide (NO) in gingival crevicular fluid. METHODS: A total of 84 patients with periimplantitis treated in Lishui People's Hospital from January 2021 to January 2024 were selected and divided into experimental group and control group, with 42 patients in each group. The control group was treated with metronidazole alone, while the experimental group was treated with Xipayi Guyin fluid on the basis of metronidazole. The levels of interleukin 6(IL-6), MMP-8, transforming growth factor α(TGF-α), and NO were compared between the two groups before and after treatment, and the number of plaques and degree of bleeding in patients were analyzed based on the plaque index(PLI) and sulcus bleeding index (SBI), and the clinical total effective rate and incidence of adverse reactions after treatment were observed. RESULTS: The total clinical effective rate of the experimental group was 73.81%, which was significantly higher than that of the control group(52.38%)(P<0.05). After treatment, the PLI, SBI, NO, IL-6, MMP-8 and TGF-α level of the two groups were obviously reduced compared to pre-treatment, and there was significant difference between the two groups(P<0.05). The adverse reaction ratio of the experimental group and the control group were 2.38% and 7.14%, respectively, with no significant difference between the two groups (P>0.05). CONCLUSIONS: The combination of Xipayi Guyin fluid and metronidazole can help inhibit the proliferation of oral pathogenic microorganisms, reduce the levels of inflammatory factors such as MPP-8 and regulate NO level. It also helps to strengthen teeth and gums, with controlling effect on the onset of periimplantitis in patients.

Key words: Periimplantitis, Xipayi Guyin fluid, Metronidazole, Matrix metalloproteinase-8, Nitric oxide