1, root canal treatment is not always completed at one time, the doctor often according to the patient’s clinical examination, step by step treatment, in general, root canal treatment is divided into 2-4 visits to complete. 2, because the root canal treatment is more complicated, requiring doctors must be familiar with the anatomical knowledge of the tooth structure and skilled operation techniques, while the need for special supporting root canal treatment instruments and equipment and materials, therefore, the root canal treatment is more time-consuming and relatively high cost. 3.During or after the completion of root canal treatment, temporary discomfort may occur, which is usually relieved by taking anti-inflammatory or analgesic drugs, and local swelling and pain should be informed to the doctor. 4, brittle teeth after treatment is best to perform inlay or crown restoration to prevent tooth fracture and extend the life of the tooth. 5, some patients with chronic periapical inflammation, the apical inflammation of the lesion at the time of treatment is in a state of rest, or just the trend of acute attacks, self-conscious symptoms are not obvious, only a slight percussion pain at the time of consultation. The doctor must use instruments to operate in the root canal, which provokes the inflammatory lesion in the resting state. If the patient has low resistance and does not take anti-inflammatory drugs in time after treatment, acute inflammation will occur and pain will be felt. If the patient’s resistance is strong, take anti-inflammatory drugs in time after treatment, and not overly tired, then, in general, it will not cause pain, and pain can be done in time to do open drainage, oral anti-inflammatory drugs and local physical therapy, and will soon return to normal.