Root canal therapy is a treatment method to prevent periapical lesions from occurring or to promote the healing of periapical lesions by removing necrotic material from the root canal, performing proper disinfection, and filling the root canal to remove adverse irritation to the periapical tissue from the root canal contents. 1, root canal treatment is not always completed in one visit, doctors often step by step according to the patient’s clinical examination, generally speaking, root canal treatment is completed in 2-4 visits. 2.Because of the complexity of root canal treatment, the doctor must be familiar with the anatomical knowledge of tooth structure and skilled operation techniques, as well as the need for special supporting root canal treatment instruments and equipment and materials, therefore, root canal treatment is more time-consuming and relatively more expensive. 3.During or after the completion of root canal treatment, there may be a short period of discomfort, which can usually be relieved by taking anti-inflammatory or painkilling drugs. 4.It is better to perform inlay or crown restoration after tooth treatment to prevent tooth fracture and prolong the life of the tooth.