Eating sweet food with sore teeth is caused by dentin hypersensitivity, mainly due to the following reasons: first, suffering from caries, caries is a chronic infection of the hard tissue of the tooth, caries will cause the hard tissue of the tooth to form a cavity. After the cavity is formed, the dentin will be exposed, and when the dentin tubules are exposed in the mouth, it will cause the soreness of teeth after eating sweet food. Second, suffering from periodontitis, most patients with periodontitis will have gum recession and root exposure, when the root is exposed in the mouth, when eating sweet and acidic food, it will cause tooth soreness. Thirdly, there are cryptic fissures on the teeth. Most of the cryptic fissures on the surface of the teeth only stay in the superficial layer of the enamel, while in some cases, the cryptic fissures are deeper, reaching the dentin or even the parts close to the nerve. For teeth with deeper fissures, when eating sweet, sour or irritating foods, the teeth will also experience soreness.