Large teeth, that is, molar teeth, large tooth grooves are also clinically referred to as sockets, because the sockets themselves have many points of fissure grooves, not easy to clean, and thus easy to become black. Usually, a lot of black in the grooves of big teeth may be related to pigment accumulation, dental caries, etc. 1, pigment accumulation: the physiological structure of the molar groove itself is not easy to clean, and the position is backward, after eating heavily colored food, such as long-term drinking of strong tea, coffee, carbonated beverages, or long-term smoking, at this time, it is easy to cause pigmentation due to inappropriate cleaning, making the groove black. At this time, patients can go to the hospital stomatology department for scaling to restore the normal color of the tooth groove; 2, tooth decay: commonly known as tooth decay, due to oral hygiene is not guaranteed, food residues corrode tooth enamel for a long time, or often eat sweets occurring tooth decay, resulting in tooth loss. Patients who suffer from oral diseases themselves, such as pulpitis and periapical inflammation, tooth decay can occur secondary to the above inflammation, resulting in blackened grooves. In this case, patients need to visit the hospital and often recover through surgical treatment. When there is a black tooth groove, in addition to the active treatment according to the doctor’s prescription, you should pay attention to the maintenance of oral hygiene in daily life, rinse your mouth in time after meals, and use dental floss to remove food residues. Eat more fresh vegetables and fruits to enhance the immunity of the body.