Worm tooth usually does not mean that there are worms inside the teeth, but a disease that causes progressive destruction of the hard tissues of the teeth under the action of many factors such as bacterial infection, food residue and bad living habits, usually called tooth decay or dental caries, often occurs during the period of children’s milk teeth or replacement of permanent teeth, generally can be divided into shallow caries, medium caries and deep caries, the difference lies in the different degrees of tooth damage. Superficial caries is only damaged in the crown area, and there are black lines on the surface of the tooth. Medium caries has obvious cavity formation, mostly no conscious symptom, but easy to be stimulated by cold, hot, acid and induce discomfort, when the stimulus disappears, the symptom will disappear immediately. Deep caries means that the middle layer and deep layer of dentin are injured, and there are deep cavities, which are close to or damaged to the pulp, and there is obvious discomfort to cold, hot and acid stimulation, which lasts for a long time. People who like to eat sweet food, can not clean the mouth timely after eating, dry mouth or wear orthodontic braces and dentures are easy to have caries. When you find that the color of teeth becomes yellow, there is demineralization in the sulcus or teeth become sensitive, such as when eating cold, hot, sweet or sour food with painful feeling, it means that there may be caries. The diagnosis should be confirmed by medical examination, stomatoscopy and X-ray, and local application of fluorine preparation such as fluorine paint, fluorine gel, etc., as well as sulcus closure and tooth filling treatment should be applied. You should brush your teeth and rinse your mouth regularly, eat less candy and cakes with high sugar content, and have regular oral examination to deal with the problems in time.