Dental treatment of tooth decay, tooth extraction and root cyst. May cause viewing discomfort. This tooth has severe cavities and a broken root, so a tooth extraction is required. The root tip is the root cyst. When cavities are placed, bacteria can spread to the root tip through the root canal. A lesion is formed at the tip of the root. In addition, if placed again, the lesion will become a root cyst. A root canal cyst remains in the cavity after tooth extraction, so use a sharp spoon to scrape it out. This patient also had a lot of tooth decay, so it was necessary to extract, so all of them were extracted. A root cyst is attached to this root. The patient was under deep anesthesia through intravenous anesthesia, so he could not feel the extraction. Low immunity due to colds and fatigue Root lesions have inflammation, sudden swelling and intense pain. Before developing to this state, it is recommended that you perform cavities and root canals. The root cyst is elastic and the cyst wall is firm. Can’t be easily broken. The inflammation caused by the tip and surrounding of the root is called apical periodontitis. Diseases caused by long-term tooth decay. Root cysts develop after this periodontitis becomes chronic.