Objective: To investigate the effects of Iroot BP on the levels of NO and LTB4 in gingival crevicular fluid and the degree of pain in patients with pulpitis. Methods: 105 patients with primary pulpitis treated in our hospital from January 2020 to January 2024 were selected as the study objects. Patients were divided into control group (52 cases) and observation group (53 cases) according to random number table method. The control group underwent direct pulp capping with MTA material. The observation group underwent direct pulp capping with Iroot BP material. Gingival crevicular fluid (NO, LTB4 levels), pain degree (VAS score), pulp and periodontal tissue clinical indicators [EPT, depth of periodontal probe, gingival redness and bleeding score] and the total incidence of complications were analyzed and compared between the two groups. Results: On day 7 and day 30 after surgery, the levels of NO and LTB4 in gingival crevicular fluid in both groups were significantly lower than those before surgery. The levels of NO and LTB4 in the observation group were significantly lower than those in the control group at 7 and 30 days after surgery (P < 0.05). 24h, 7d and 30d after surgery, VAS scores in both groups were significantly lower than those before surgery; The VAS scores of the observation group at 24h, 7d and 30d after surgery were significantly lower than those of the control group (P < 0.05). 30 days after surgery, EPT, periodontal probing depth, gingival redness and bleeding scores of both groups were significantly decreased, and EPT, periodontal probing depth, gingival redness and bleeding scores of observation group were significantly lower than those of control group (P < 0.05). The total complication rate of the observation group was significantly lower than that of the control group (P < 0.05). Conclusion: Iroot BP can reduce the level of NO and LTB4 in gingival crevicular fluid, relieve pain, improve clinical indexes and reduce complications in direct pulpitis pulpitis.