When the fistula of a tooth has been cleaned up, the nerve has been severed, and the tooth has not been extracted, a filling is needed to restore the chewing function of the tooth and to maintain the effectiveness of the treatment. Most of the affected teeth that have undergone pulpal inflammation and fistula abscesses have large cavities and should be filled after other treatments have been perfected so that the affected teeth can continue to perform their functions, contributing to the stabilization of the dentition in the mouth and the health of the digestive system. If the tooth is not filled, the chewing efficiency of the affected tooth cannot be restored, and at the same time, the bacteria in the mouth can enter the periapical tissue through the root canal, and the affected tooth will once again develop fistula pus and other symptoms. If the patient has the condition of restoration should be timely crown restoration to prevent tooth splitting. It is recommended to go to the hospital for professional treatment with the help of a doctor.