It is not necessary to extract the tooth after root canal failure. Observation, retreatment, surgical treatment or extraction need to be considered after evaluation of the condition based on clinical symptoms. 1. Follow-up observation and evaluation of the condition. If clinical symptoms appear in a short period of time after root canal treatment, but the x-ray examination of the heel root is well filled with periapical no lesions; x-ray film appears to be around the bone destruction, but the tooth loosening degree is small root canals are properly filled; the apical translucency shadow is not narrowed after the root canal retreatment, it can be followed up and observed first. 2. Retreatment. Failure of root canal treatment may be due to imperfect root filling or incomplete control of inflammation within the root canal, depending on the situation, re-treatment can be considered. 3. Surgical treatment. If root canal treatment fails and the cause is infection or cyst outside the root canal, apical surgery can be chosen for treatment. 4. Extraction. Only when the affected tooth has no value for preservation, then the affected tooth needs to be extracted. The specific need to do a complete oral examination to determine whether the need for extraction, you can consult a professional physician’s opinion.