Dark spots on teeth

Some people drink or eat foods that are easy to stain for a long time, or have long-term exposure to certain minerals, such as gargle with potassium permanganate water for a long period of time, and mercury can be exposed to silver nitrate to treat oral diseases. Can make your teeth black. Contact with iron, sulfur and other substances, easy to make the teeth appear black and green. In addition, enamel hypoplasia, dentin hypoplasia, hereditary opalescent teeth, fluorosis, tetracycline teeth, and dental caries can cause teeth to appear yellow, brown, and black.