Sore teeth from eating sweet may be caused by dental caries, periodontitis, dentin sensitivity and so on. 1. Dental caries: Dental caries is an infection of the hard tissues of the teeth, which may cause chipped teeth and expose the dentin tubules. When the dentin tubules are exposed, it will cause toothache when it encounters sweetness, coldness, heat, and so on. 2. Periodontitis: Periodontitis is a chronic inflammation caused by bacteria in plaque that invade the periodontal tissues. With the development of the disease, teeth loosening and gum recession will gradually occur, which will cause toothache when encountering sweet, sour and cold. 3. Dentin sensitivity: when the tooth enamel is destroyed, exposing the dentin, dentin sensitivity will occur, eating sweet and sour food will be easy to stimulate, causing dentin temporary sensitivity discomfort, toothache. Patients who have sweet toothache should go to the dentistry department of the regular hospital in time to clarify the cause of the disease and then actively treat it.