If the tooth splits after root canal treatment, it needs to be treated in different ways such as filling and extraction according to the degree of splitting. 1, if only the crown splits and the scope of splitting is small, the split part of the crown can be removed and the remaining crown can be temporarily filled with filling material according to the condition of the remaining crown, and adult patients can also choose porcelain crown restoration to restore the shape and function and prevent the tooth from fracturing or 2. If the degree of splitting is large and has reached the subgingival level or even the root of the tooth is cracked, the root canal treated tooth needs to be partially or completely extracted. After the alveolar bone is stabilized, a denture can be used to restore the function of the tooth; 3. If the splitting has occurred in one of the roots of a multi-rooted tooth, a hemisection can be considered, i.e., the diseased part is removed and the other half is treated for restoration. After root canal treatment, the tooth becomes fragile due to the lack of nutrient supply from the pulp, and is prone to splitting when encountering larger chewing forces. Take care to avoid eating excessively hard food and seek medical consultation promptly when painful symptoms appear.