A chewing tooth with only the root remaining generally refers to a case where only the root remains and the crown is missing due to damage or decay of the posterior molar. The amount of remaining tooth tissue should be examined, and if the remaining root is still supragingival and strong, the root can be utilized in most cases. A systematic root canal treatment is performed for the root, and then a metal or fiber post is placed in the root canal, and the tooth is restored by applying a post-and-core crown, so that this root can continue to perform its chewing function. If the caries or damage is deep and the root is significantly loose, the tooth can only be extracted and the missing tooth can be restored by implant restoration or active restoration.