The success rate of root canal surgery is as follows: 1, first of all, determine whether the patient to carry out a more complete system of root canal treatment, root canal treatment steps and examination is very detailed, after a more complete treatment, the success rate of about 80% -90%, the data is mainly for primary apical periodontitis, did not do the relevant treatment of the patient; 2, if the patient is in other outside hospitals or have done the root canal treatment, the re-emergence of If the patient has already undergone root canal treatment in another institution or has already had an attack of apical periapical infection, the treatment required is called root canal retreatment. The root canal system of the tooth undergoing root canal retreatment may be more complicated itself, or the root canal may not be smooth after a certain amount of treatment, the success rate of the treatment is lower than that of the first treatment, and it depends entirely on the original treatment, and there may only be about 50% success rate, therefore, it is recommended that patients with apical periapical infection undergo a better and more formal root canal treatment in an early stage. Therefore, it is recommended that patients with periapical infections undergo a better and more formalized root canal treatment at an early stage.