If there are black things at the gums; 1. Consider if there is an embedding of food. If the black stuff disappears, it usually proves that there is only food embedment. 2.Tartar may also accumulate in the gum pocket, so it is necessary to carry out full mouth cleaning in time, then patients can use toothpicks for self-examination, if the black food is hard, then it is considered to be calculus at this time. 3, is the occurrence of dental caries at the gum, this is relatively rare, because dental caries mostly occurs on the surface of the teeth and the adjacent surface of the teeth, in the root of the teeth rarely occurs. But there are some patients who have caries in this position by unclean brushing. Then through the patient’s self-examination, it can be found that the tooth not only has a color change, but also the tooth body has a certain amount of defects, so it is necessary to carry out filling treatment in time.