Black incisor gap may be food impaction, caries, pigmentation, tartar, gum recession and so on. 1. Food impaction: food debris stuck in the gap between the incisors may be manifested as black incisors. 2. Caries: caries on the neighboring surface of the incisors may be manifested as a black incisor gap. 3. Pigment, tartar: pigment, tartar attached to the surface adjacent to the incisors, may be manifested as the gap between the incisors black. 4. Gum recession: the gap between the incisors should be filled with gingival papillae, if there is gum recession, it will show a black triangle state, like the incisors gap black. Incisor gap black may also have other pathological factors, it is recommended to go to the hospital in a timely manner, improve the examination to clarify the cause of the disease, under the guidance of the doctor to give targeted treatment or treatment.