There are several possibilities for black teeth: First, tooth decay, tooth decay is easy to demineralize and cavities appear, in this case, the teeth are defective in the film examination, so it is necessary to do dental filling, that is, fillings. Second, the black tooth may also be due to the plaque attached to the tooth surface to produce dental stains, this situation needs to be scaled, if the stains have reached the subgingival scraping treatment, and local rinse and medication. Third, the black teeth may also be due to pulp necrosis, pulp necrosis of the teeth will appear gray-black or black-brown, you can do root canal treatment, and do the teeth bleaching, or do porcelain braces or dental veneers repair. Fourth, the black teeth may also be due to tetracycline or fluorosis teeth produced.