There are mainly two possibilities for black stuff on teeth: the first possibility, pigmentation, some people like to drink strong tea, coffee and other beverages containing pigment for a long time, which will form black pigmentation on the surface of teeth after a long time, in this case there is no hard tissue defect, and the conventional scaling will be able to remove these pigments. The second possibility is that there is already a cavity on the tooth surface, in this case there is not only black pigment on the tooth surface, but also demineralization and defect of the hard tissue of the tooth. In this case, it is necessary to go to a regular dental institution for treatment of dental caries, to remove the decayed and decayed hard tissues on the surface of the teeth, and to restore the original shape of the teeth by using resin filling.