Especially for residual crown and residual root teeth, the restorative department needs to perform post and crown restoration, and root canal therapy is the only treatment method that can be selected. In general, for those pulpitis, pulp necrosis, various types of apical periodontitis are suitable for root canal treatment. According to clinical reports, the success rate of root canal treatment is more than 90%, which is the best treatment method to save the affected teeth. The process of root canal therapy is that the doctor uses special instruments for root canal treatment to completely remove the infected pulp, infected dentin and toxic decomposition products, and after root canal irrigation, disinfection and strict filling of the root canal, to prevent bacteria from entering the root canal and reinfection. , to prevent the occurrence of periapical lesions or promote the healing of periapical diseases. Fourth, the degenerative changes of the dental pulp caused by unknown reasons, such as root canal absorption, pulp stone caused by the pathological changes of the dental pulp. Apicitis caused by drugs during electrical stimulation and endodontic treatment. Root canal treatment Third, the infection of the apex of the pulp caused by physical and chemical reasons, such as: pulp irritation caused by poor temperature of the bottom after filling, root canal treatment with different metals Second, any reason (including pulp Root apical lesions caused by the continued development of inflammation, the failure of plastination treatment, and the retrograde infection of periodontitis. Pulpitis and pulp necrosis cannot preserve viable pulp. Root canal treatment First, the indications for root canal treatment caused by any cause (including caries, cracks, coronal fractures, deformed central apex, excessive wear, retrograde infection of periodontal disease, accidental pulp penetration): root canal treatment is aimed at A course of treatment for tooth, pulp, and root apical lesions. Root canal therapy is to remove the necrotic material in the root canal, carry out proper disinfection, and fill the root canal to remove the adverse stimulation of the root canal contents to the surrounding tissue, prevent the occurrence of periapical lesions or promote periapical lesions. A healing method.