Objective To explore the effect of nickel-titanium rotary root canal therapy on tooth preservation effect and facial aesthetic satisfaction in patients with chronic apical periodontitis. Methods A total of 90 patients with chronic apical periodontitis admitted to Suzhou Stomatological Hospital from January 2023 to June 2025 were selected, and they were divided into the control group and the observation group by the random number table method, with 45 patients in each group. The control group was treated with conventional syringe irrigation, and the observation group was treated with nickel-titanium rotary root canal therapy. The tooth preservation effect, facial aesthetic satisfaction and periodontal health indicators were compared between the two groups. Results The total effective rate of tooth preservation in the observation group (95.56%) was higher than that in the control group (75.56%) (P<0.05). The facial aesthetic satisfaction rate in the observation group (97.78%) was higher than that in the control group (82.22%) (P<0.05). The PD, GBI, PLI and CAL in the observation group after treatment were better than those in the control group (P<0.05). Conclusion The application of nickel-titanium rotary root canal therapy in patients with chronic apical periodontitis can improve the tooth preservation effect, enhance patients' facial aesthetic satisfaction and improve their periodontal health status, which is worthy of clinical application.