A tooth with a rotten hole that has lost a piece needs to be treated depending on the exact extent of the damage. If the defect is small, a filling can be placed. If the defect is large, a root canal can be performed. If the damage is severe and untreatable, extraction can be considered. 1. Filling: If the patient’s tooth is small and does not have any obvious symptoms of discomfort, the tooth can be filled after cleaning the mouth. 2. Root canal treatment: If the patient’s tooth has a large defect, or if there are obvious pain and other symptoms of discomfort, causing pulpitis or periapical inflammation, root canal treatment is usually required, and then restorative treatment can be carried out after the tooth’s symptoms of discomfort are eliminated. 3. Extraction: However, if the patient’s tooth is so badly damaged that it can no longer be repaired and used normally, the tooth is usually considered to be extracted in order to avoid adverse effects. Therefore, if a tooth has a rotten hole and a piece of it has fallen out, you should go to the hospital for diagnosis and treatment in time to avoid delaying the condition.