If the tooth is not painful but chewing something is painful, first of all, you can check whether there is food embedment in the teeth, under the long time embedment, it is easy to cause the pain of gum when eating. If there is no food embedding, you need to consider some disease factors, such as tooth sensitivity, caused by dental caries, and may be caused by dental inflammation, hidden tooth fracture, etc.: 1, tooth allergy: some patients themselves when the teeth are sensitive, daily may not be painful, but when eating too cold, too hot, too sweet, too acidic and other irritating food, chewing aggravates the stimulation of food on the teeth, thus producing rapid, short-lived sharp pain. It is recommended to adjust the daily eating habits to avoid stimulating the teeth, and if the symptoms are serious, the desensitization treatment of teeth can be carried out according to the doctor’s prescription; 2.Dental caries: it is often caused by unhealthy eating habits and not paying attention to dental care, and is a kind of destructive disease of dental tissue. It shows as plaque or cavity on the surface of teeth, and when chewing food, food stimulation can induce the pain of tooth decay. Generally, it can be treated by crown restoration or filling, and if it is more serious, the carious tooth can be extracted; 3, tooth inflammation: such as pulpitis, which is an inflammation occurring in the tooth pulp tissue, often developed from tooth decay. When chewing, teeth and food friction, extrusion, will produce certain stimulation to the pulp, and then induce the appearance of pain, can be clear through X-ray examination, generally through pulpotomy, or direct or indirect pulp capping surgery, etc. for treatment. In addition, periapical inflammation can also cause toothache when chewing. The acute inflammatory phase can be accompanied by fever and local swelling, while the chronic phase is mainly characterized by toothache when eating, occasionally accompanied by abscesses. Whether in the acute or chronic phase, it is recommended to actively seek treatment. In the acute phase, drainage of pus may be required, and when the inflammation is controlled or in the chronic phase, root canal therapy is commonly used to cure periapical periodontitis; 4. Occult tooth fracture: It is a pathological crack appearing on the tooth surface, often related to trauma and overbite. Under close examination, black lines are visible on the tooth, which cause the appearance of pain during chewing due to food extrusion and friction of the tooth. It can be treated by adjusting the bevel of the tooth tip to improve the force.