Darkening of tooth roots can be seen in a variety of situations, such as tetracycline teeth, dental fluorosis, etc. Smoke stains from long-term smoking or lack of attention to oral hygiene cleaning, causing plaque, tartar, tartar, etc. to attach to the roots of the teeth, or wearing metal crowns, can cause the roots of the teeth to become dark. In addition, oral diseases such as caries and endodontic disease, as well as systemic diseases such as Addy’s disease, can also cause the roots of teeth to become black. The blackening of tooth roots can be improved by scaling, restoration and treatment of the original disease. Scaling: Scaling through professional oral instruments to remove tartar, plaque, tartar and long-term smoking stains, and polishing treatment of the tooth surface can make the tooth surface white and shiny, which can help improve the situation of black roots. Secondly, restoration: for cases such as tetracycline teeth and fluorosis, veneer restoration, porcelain crown restoration or composite resin restoration can be carried out. At the same time, we should actively prevent the occurrence of caries, try to avoid the use of tetracycline drugs and reduce the intake of water containing fluoride. For the blackening of tooth roots caused by wearing metal crowns, generally it will not affect human body and can be left untreated, if treatment is strongly requested, the crown can be replaced. However, it should be noted that replacing the crown is risky and may lead to loosening of the tooth, so if there is no abnormality, it is not recommended to replace it at will. C. Treatment of primary disease: 1. Caries: choose different treatment means according to the depth of caries, blackening of tooth root is common in root surface caries, the decayed tooth tissue should be removed, and then choose suitable material for filling. If the decayed part is too deep, root canal treatment should also be carried out, and crown restoration should be carried out as appropriate; 2.Pulp disease: If the pulp disease has caused pulp necrosis, the root of the tooth can appear black, and root canal treatment is needed. If the tooth is already seriously loose, the tooth can be considered for extraction to avoid affecting the growth of surrounding healthy teeth; 3, Addison’s disease: that is, hyperalgesia, which may lead to the blackening of the root of the tooth connected to the gum area, the original disease needs to be treated in a timely manner, and can be treated with glucocorticoids, salt corticosteroids, etc., as prescribed by the doctor, and the adrenal crisis needs to be supplemented with fluids in a timely manner to avoid dehydration. Since there are many reasons for the blackening of the roots of the teeth, patients are advised to visit a dentist to identify the cause and treat it under the guidance of the doctor.