If the root resorption of a baby tooth after root canal treatment results in an abscess, it may be due to the fact that the remaining nerve has not been removed cleanly or the apical inflammation has not been controlled, so depending on the situation, we may choose to perform a new root canal treatment or extract the baby tooth. 1. Re-endodontics: If the lesion of the baby tooth is relatively limited and does not affect the succeeding permanent tooth, it is necessary to completely remove the filling material from the original root canal and re-endodontically treat it. 2. Extraction of milk teeth: If the inflammation of milk teeth has spread to the succeeding permanent teeth, it is better to extract the milk teeth to facilitate the normal eruption of permanent teeth. After the root canal treatment of the milk tooth, the pus should go to the hospital in time to take pictures of the root tip of the tooth and the condition of the permanent teeth, and then choose the most reasonable treatment plan under the doctor’s advice, so as not to affect the development of the inherited permanent teeth.