Tooth pain can not bite things, mainly caused by the following three reasons: First, the patient has suffered trauma, trauma makes the tooth fracture, this time there will be more obvious bite hard things feel pain, and even can not bite the performance of food, need to consider the tooth through the X-ray to stay. The second, tooth pain is likely to be periapical, periapical periodontitis is the biggest performance is the tooth will have a floating feeling, and in biting hard objects will appear severe pain, this time you can determine the severity of periapical periodontitis through X-ray for the next step of treatment. Thirdly, if the tooth is painful and cannot bite, it is likely that the periodontal abscess is caused by severe periodontitis. If the patient has a large amount of calculus in the mouth, there is a high probability of suffering from periodontal abscess at this time, you need to go to the periodontal department in time to receive systematic periodontal treatment, and for the periodontal abscess also need to take oral antibiotic drugs to avoid the emergence of systemic infection.