Objective To analyze the effect of bracketless invisible appliance on periodontal health indicators in patients undergoing orthodontic treatment. Methods A total of 125 patients undergoing orthodontic treatment admitted to Shanghai Ninth People's Hospital from January 2022 to December 2024 were selected. According to different treatment plans, they were divided into the reference group (n=62) and the observation group (n=63). The reference group was treated with fixed appliance, and the observation group was treated with bracketless invisible appliance. The clinical efficacy, periodontal health indicators and inflammatory factor levels in gingival crevicular fluid were compared between the two groups. Results The total effective rate of the observation group (90.48%) was higher than that of the reference group (75.81%) (P<0.05). At 6 months after orthodontic treatment, the periodontal health indicators in the observation group were better than those in the reference group (P<0.05). At 6 months after orthodontic treatment, the levels of sICAM-1, TNF-α and MMP-8 in the observation group were lower than those in the reference group (P<0.05). Conclusion Bracketless invisible appliance demonstrates good efficacy in orthodontic treatment, which can effectively maintain patients' periodontal health and reduce the levels of inflammatory factors in gingival crevicular fluid. It is worthy of clinical application.