The blackness in the middle of the gap between two teeth may be caused by pigmentation, which can be treated by scaling; it may also be caused by caries, which requires medication and surgery according to the cause. 1. Hyperpigmentation: If you don’t pay attention to oral hygiene, it may lead to black pigmentation in the middle of the teeth, and then you can remove the calculus on the surface of the teeth and the black material through ultrasonic scaling. 2. caries: for caries-induced blackness in the middle of the gap between the two teeth need to be under the guidance of the doctor with 75% sodium fluoride glycerin paste, 8% stannous fluoride solution and other preparations containing. In addition, you can also take surgical restorative treatment, such as inlay restorative surgery, composite resin filling surgery. It is recommended that patients with black teeth need to consult a doctor in a timely manner and follow the doctor’s instructions for treatment. In addition, you need to develop the habit of brushing your teeth in the morning and evening, and you need to rinse your mouth in time after each meal to keep your mouth clean. In addition, the diet should eat less candy, candied fruit and other too sweet food.