A rotten tooth with a cavity is actually a cavity of caries. If there is pain, it may be caries, or it may be secondary to acute pulpitis or periapical inflammation. When the tooth is infected by bacteria due to various reasons, it gradually erodes the tooth and cavity will appear. Patients need to check first to clarify the type of disease, and then carry out targeted treatment: 1. Caries: when the tooth has medium caries or deep caries, it is more sensitive to hot and cold stimulation and easy to produce pain, but usually there is no spontaneous pain. Patients need to consult the doctor in time, if it is medium caries, the bacteria on the surface of the tooth and the decayed tissue will be removed completely, and then the filling treatment will be carried out, which is often said to be filling. If it is deep caries, the caries is close to the pulp, indirect pulp capping can be used first to promote softened dentin remineralization and restorative dentin formation, and then fill the tooth; 2. Acute pulpitis: If the toothache is very serious, it can be painful without causation, often at night, it is usually acute pulpitis, usually choose root canal treatment, that is to remove the diseased pulp tissue on the basis of preserving the affected tooth, it can be performed through local anesthesia After the pulp is removed, the cavity can be filled to relieve the symptoms; 3, periapical inflammatory disease: refers to inflammatory disease occurring in the tissue around the root tip of the tooth, spontaneous pain, biting pain, and the pain is gradually aggravated, root canal treatment can also be used to remove the root pulp and reduce the infected material in the root canal to ensure a smooth root canal and reduce inflammation, and then tightly fill the root canal The root canal can be filled tightly to achieve the treatment purpose. In case of acute suppuration, the abscess can be incised and drained to gradually relieve the painful symptoms. In addition, for patients with significant pain and unable to seek medical treatment for a short period of time, drugs such as oral ibuprofen and acetaminophen can also be administered to help relieve pain. After treatment, patients should pay attention to the daily cleaning of the mouth and periodontium, brush the teeth in the morning and evening, rinse the mouth in time after eating sweet and spicy food, and scaling the teeth regularly every year to help reduce the incidence of caries or other inflammatory diseases.