Black coloration on the teeth is generally seen for two reasons. One is exogenous coloring and the other is endogenous caries. Exogenous staining mainly refers to poor dietary habits, for example, if someone smokes a lot, drinks tea and coffee regularly, which have a distinctive color, then smoke stains, tea stains and the corresponding pigmentation will remain in the mouth, and over time you will find that the surface of the teeth is visibly blackened. Can be sandblasted and polished way to make the surface of the teeth clean again, relatively speaking, less harmful, but there are also blackened teeth is due to the production of caries, which is usually referred to as tooth decay, once formed means that there has been damage to the internal dentition, must go to a professional stomatology for caries to remove the decay and filling treatment.