Dark stains on teeth may be caused by pigmentation, calculus, plaque, caries and other conditions, which can be treated by dental cleaning, restoration of caries and other ways. 1. Hyperpigmentation: drinking strong tea and smoking for a long time will lead to pigmentation on the surface of the teeth, which can be removed by brushing, and if brushing can not be completely removed, ultrasonic scaling, polishing and rinsing can be carried out to effectively reduce the pigmentation of the teeth. 2. Dental calculus: Occasionally black dental calculus, which can be manifested as black spots on the teeth, can be removed by choosing supragingival cleaning and subgingival cleaning, and it is also necessary to develop the habit of brushing and rinsing the teeth diligently. 3. Plaque: Black stains on teeth may be plaque, which requires ultrasonic cleaning. After removing plaque, you should pay attention to rinse your mouth in time after meals to prevent food debris from accumulating on your teeth. 4. Dental caries: Dental caries can also lead to black stains on teeth, which need to be cleaned up, and then selected according to the caries filling restoration. If it is accompanied by pulpitis, root canal treatment will be carried out before restoration. Teeth on the black stains are recommended to go to the hospital stomatology examination in a timely manner to determine the cause of the disease and then treatment, so as not to delay the condition.