Some people appear black on the teeth can not be brushed off, is due to ageing, dentin calcification deposits, so that the teeth become yellow or black. Long-term consumption of food containing pigment and improper cleaning can cause pigmentation, and may be caused by the role of drugs or dental caries, resulting in black teeth above the brush can not be removed: 1, pigmentation: long-term smoking or drinking a lot of coffee, strong tea and other beverages containing pigment, as well as long-term chewing betel nut, may be left on the teeth, such as cigarette stains, coffee stains and other pigmentation, can be manifested as the tooth surface or occlusal surface It is difficult to remove them completely by ordinary brushing. Should reduce pigmented food intake, try to quit smoking, can be improved by scaling, tooth bleaching, through the application of dental bleaching drugs or cleaning apparatus to remove the color stains on the teeth; 2, the role of drugs: long-term use of fluoride or tetracycline drugs patients, may be due to drug deposition or make teeth coloring and lead to teeth appear black-brown or gray-black, for dental fluorosis, tetracycline teeth, generally occur in the teeth developmental stage. It can be improved by dental bleaching, laser treatment, etc. It is recommended to go to the hospital for dental bleaching treatment by doctors to avoid oral damage caused by lack of dose control, and laser acts on pigment particles through specific wavelengths, which also helps to whiten teeth; 3, dental caries: due to food or bacteria attached to the tooth surface for a long time, thus causing corrosion and decay on the tooth surface, and with the progress of lesions, the color change of teeth is more With the progress of the disease, the color of the teeth will change more obviously, leading to the blackening of the patient’s teeth, and there will be tooth loss, which can be treated by remineralization or surgical removal of the decayed tissue and restoration treatment according to the degree of decay.