Inability to bite hard things due to dental hypersensitivity should refer to dentin hypersensitivity. However, the inability to bite hard things may also be due to periodontal disease, apical periodontitis, cryptic fracture of the tooth and so on. It is necessary to find out the specific cause and choose desensitization treatment, periodontal treatment, root canal treatment, filling and restoration and other treatment methods. 1. Dentin allergy: dentin allergy caused by the inability to bite hard things, you can choose to use anti-allergy toothpaste brushing or desensitization treatment, the formation of parenchymal defects need to be filled and repaired. 2. Periodontal disease: periodontal disease caused by tooth sensitivity can not bite hard things, the first choice of supragingival cleaning and subgingival scraping, and then according to the situation of the sequence of periodontal treatment. 3. Apical periodontitis: the tooth sensitivity caused by apical periodontitis can not bite hard things, it is best to carry out root canal treatment on the tooth in time, and then carry out crown restoration in the later stage. 4. Cracked tooth: When the cracked tooth is shallow, choose the filling repair, when the cracked tooth is deep, choose the root canal treatment to relieve the tooth sensitivity and can’t eat hard things. Tooth sensitivity can not bite hard things in time to the hospital examination, clear causes and active treatment, so as not to aggravate the symptoms of tooth sensitivity.