Dentin sensitivity, commonly known as “inverted tooth”, mainly refers to the transient and sharp pain produced by cold, hot, sour, sweet and other stimuli. The main reason is due to the use of toothbrushes with too hard bristles, brushing too hard, brushing incorrectly resulting in enamel defects in the neck of the teeth, or long-term chewing of hard food, night grinding resulting in tooth wear, or gingival recession resulting in dentin exposure. For the prevention and treatment of dentin sensitivity, it is recommended to: ① rinse the mouth after meals; ② reduce the intake of acidic foods and drinks; ③ do not brush the teeth immediately after eating acidic foods and drinks, and then brush the teeth one hour later; ④ choose qualified toothbrushes, use the correct brushing method, and avoid brushing with excessive force; ⑤ use anti-sensitive toothpaste, and if there is no obvious effect after 4-8 weeks, you should seek medical advice.