Toothache is a medical condition called hypersensitivity, which is caused by wear and tear of the tooth surface or gum recession that exposes the roots of the tooth, causing thousands of tiny holes in the tooth to penetrate into the pulp. Patients may experience soreness when their teeth are cold or hot, or they may feel soreness when they are pricked with a toothpick due to a mechanical stimulus, which is sharp and sudden and can penetrate deep into the pulp and roots of the teeth. The causes of this tooth allergy: first, improper brushing, many people brush their teeth is the implementation of horizontal brushing, saw-like, brushing damage teeth to form a groove, this way the dentin exposed after the soreness; second, patients who have the habit of grinding their teeth at night, the enamel surface wear after the dentin exposed will also appear soreness; third, now people like to chew betel nut, betel nut fiber on the tooth surface wear is Fourth, some patients wear dentures, the corresponding ring hook position is not placed properly, take the bad habit of wearing after the formation of tooth surface wear.