Abstract： Objective:To explore the role of digital apical film combined with cone beam computed tomography (CBCT) in the evaluation of curative effect and prognosis of root canal therapy (RCT).Methods:The clinical data of 84 patients who underwent RCT, including 45 males and 39 females, aged (42.7±10.4) years, in Cangzhou People's Hospital from January 2021 to December 2021 were analyzed retrospectively. The patients were divided into observation ( n=42) and control ( n=42) groups using the random number table method. Apical film was used to assist in the RCT of the control group, and apical film combined with CBCT scanning was used during the RCT of the observation group. A total of 54 teeth, including 11 maxillary first molars, and 12 maxillary second molars, 13 mandibular first molars, and 18 mandibular second molars were observed in the control group. A total of 56 teeth were detected in the observation group, exactly 13 maxillary first molars and 10 maxillary second molars were recorded, respectively, meanwhile, 14 and 19 mandibular first and second molars were identified, respectively. Proper filling rates and qualified rates of dense root canal filling of the maxillary first and second molars and mandibular first and second molars in two groups were compared by χ2 test. Results:The control group showed lower proper filling rates of the maxillary first molars and mandibular second molars compared with the observation group (65.71%(23/35) vs. 88.10%(37/42), 68.29%(28/41) vs. 87.50%(42/48)), and the differences were statistically significant ( χ2=5.560, 4.858; both P<0.05). The control group also presented lower proper filling rates of maxillary second molars and mandibular first molars than the observation group (71.43% (25/35) vs. 85.71% (24/28), 74.00% (37/50) vs. 86.27% (44/51)), but the differences showed no statistical significance ( χ2=1.837, 2.395; both P>0.05). A lower qualified rate of dense root canal filling was observed in the control group than that in the observation group (68.52% (37/54) vs. 85.71% (48/56)), and the difference was statistically significant ( χ2=4.630, P<0.05). The control group exhibited a lower cure rate after three revisits compared with the observation group (76.19% (32/42) vs. 92.86% (39/42)), and the difference was statistically significant ( χ2=4.459, P<0.05). Conclusions:CBCT combined with digital apical film as evaluation methods for the curative effect of RCT, the evaluation of the length and severity of root canal filling of RCT becomes more accurate and can effectively improve the prognosis of patients.