Whether or not a tooth stump can be left unextracted for life depends on the specific situation. If a tooth stump is completely usable after a radiograph, a perfect root canal treatment can be performed, and after the root canal treatment, a porcelain crown can be restored using the tooth stump so that it can be preserved. If the apical lesion is serious, the section of the root reaches below the gum, is deep, and the root is small, curved, etc., and cannot be used, then such a root should be considered for extraction. The main reason for extraction is that such stumps often cause apical inflammation and have no value for retention, and only after extraction of the stumps can better restorative treatment be carried out, including dental implants, including movable dentures or fixed denture repair. If you can’t keep the residual root in your mouth for a long time, it can irritate your gums, tongue, buccal mucosa, etc. The long-term irritation may cause mucosal lesions or even cancerous conditions. Therefore, for a root that can be used, retained, and restored, it should be restored by perfect root canal treatment, and for a root that cannot be restored or used, it should be extracted as soon as possible.