Root treatment, if older patients are considering an overdenture, may consider treatment of the root, mainly root canal therapy, which preserves the height of the local alveolar bone and reduces the local resorption of the bone. If the root has significant inflammation, the root canal treatment will be very ineffective and extraction will be considered at this time because it may be locally known as an infectious factor. Therefore, the extraction or non-extraction of a tooth root requires a clinical examination to determine whether the root is worthy of treatment. If the root is likely to be retained after treatment or if the root can be restored with a pile crown, it can be retained; if the root is poorly treated and will lead to recurrent local inflammation, it should be extracted as soon as possible.