Tooth root canals exposed old inflammation of common diseases for pulpitis, periodontitis, etc., the causes of different treatment methods are different, specific analysis is as follows: 1. Pulpitis: The primary goal in treating pulpitis is to save the pulp, followed by saving the affected tooth. Methods of pulp preservation include pulp capping and pulpotomy. If the pulp has become irretrievably diseased, it should be removed. The method of preserving the affected tooth is root canal therapy. Oral hygiene, such as brushing and rinsing, should be maintained during treatment. 2. Periodontitis: Periodontitis can be treated with medication and surgery. Drug treatment generally take tinidazole, metronidazole, minocycline, as well as benzylpenicillin and roxithromycin, etc., the specific precautions should follow the doctor’s advice. Surgical treatments include flap surgery, bone grafting and dental implantation. Patients should pay attention to oral hygiene before surgery to ensure that they can tolerate the surgery, should not brush their teeth after surgery, avoid using the surgical site for chewing and should be reviewed regularly.