Depending on the condition of the patient’s cavity, it can be treated by filling, extraction and veneering, as well as root canal treatment. 1. Filling: Tooth decay, a bacterial disease, can be secondary to pulpitis and periapical inflammation. If the cavity is small, it can be treated by surgically removing the decayed tissue, preparing the cavity into a prescribed shape, and filling the cavity with artificial material to restore the form and function of the tooth. At present, the main treatment techniques are composite resin filling and glass ionomer filling. 2. Tooth extraction: If the development of caries is serious, destroying the structure of the tooth, which can not be retained, this is the worst case of tooth decay, and the diseased tooth needs to be extracted. If it is a tooth that has a big impact on chewing, it needs to be replaced after extraction. This is also one of the treatments for tooth decay. 3. Root canal treatment: If the crown of the decayed tooth has been very seriously eroded and the pulp has been exposed, root canal treatment will be needed. The infected pulp in the root canal is cleaned out, and then the root canal is sterilized and disinfected. Finally, the root canal will be filled with a filling material to restore the decayed tooth to its normal shape and basic function. If you experience symptoms related to tooth decay, it is recommended that you visit a hospital in a timely manner for early treatment.