The reasons why teeth hurt when you bite something without biting include apical periodontitis, dental caries, dentin hypersensitivity, etc., which can be solved by root canal treatment, medication, and surgical treatment. 1. Periapical inflammation: When the bacterial growth in the pulp cavity leads to infection, it is easy to affect the periapical surrounding tissues and produce inflammatory reaction, showing the symptom of pain when biting. Generally, after eliminating the infection in the root canal, the periapical inflammation will also be gradually eliminated. Root canal treatment can be used to drain the inflammatory material, and at the same time, metronidazole and ibuprofen can be used in combination to reduce inflammation and relieve pain. 2. Dental caries: If the carious cavity has penetrated deep into the dentin, it will cause irritation to it, and then the phenomenon of tooth biting pain will appear. For this kind of problem, it is necessary to repair the breakage through composite resin direct bonding restoration, inlay restoration, etc.. Secondly, if the condition is mild, cyanide or silver ammonia fluoride can also be used to control the condition. 3. Dentin allergy: When the teeth are subjected to mechanical friction or abnormal temperature of food, it will produce strong pain. It is also accompanied by red and swollen gums, easy bleeding and other problems. For patients with mild disease, dental desensitizer can be used to make the allergic area form a protective film. Dental materials can also be used to fill the area to avoid further localized irritation. There are many reasons why your teeth hurt when you bite something, and it is important to seek medical attention and dental treatment or medication as prescribed by your doctor after symptoms occur.