Objective To explore the efficacy of synchronous application of crown restoration and root canal treat-ment for cracked-tooth syndrome. Methods Ninety-eight patients with cracked-tooth syndrome in a hospital in Hubei from January 2018 to June 2019 were selected as the study subjects

and the patients were divided into ob-servation group（n=49） and control group（n=49） using a random number table. The patients in the control group were treated conventionally

and the patients in the observation group were treated with crown restoration and root canal treatment simultaneously

and the treatment for patients in both groups continued for 6 months. The number of visits

treatment time

treatment efficacy and pain at 7 d of treatment were compared between the two groups

and the functional changes of the teeth before and at 6 months of treatment were compared between the two groups. Results The number of visits in the observation group was 2.41±0.51

which was significantly less than that the control group’s 3.65±0.71

and the treatment time was（13.24±1.23）d

which was signifi-cantly shorter than that in the control group（21.58±2.69）d. The differences were statistically significant（P<0.05）. The total treatment efficiency of patients in the observation group was 97.96%

which was significantly higher than that of 81.63% in the control group

and the difference was statistically significant（P<0.05）. The incidence of pain in the patients of the observation group at 7 d of treatment was 20.41%

which was significantly lower than that of the control group（40.82%）

and the difference was statistically significant（P<0.05）. Be-fore treatment

there was no statistically significant difference in the bite force

chewing efficiency

and tooth loosening between the 2 groups（P>0.05）. At 6 months of treatment

the bite force and chewing efficiency of the patients in the observation group were significantly higher than those in the control group

and the tooth loos-ening was significantly lower than that in the control group

and the differences were all statistically significant（P<0.05）. Conclusion The simultaneous application of crown restoration and root canal treatment for crypto-clastic endodontic disease has obvious effects

which can significantly reduce the number of patient visits

shorten the treatment time

effectively relieve pain and improve tooth function

and has a high value for promotion and application.