There is a hole in the tooth but no symptoms of pain, does not mean that the teeth are not decayed, only the depth of the cavity from the nerve there is a certain distance, the patient’s feeling is not very sensitive, but in fact the teeth have been decayed. Specific how to treat the need for patients to the regular hospital stomatology, first of all take an X-ray for examination. The cause of cavities is mainly due to careless brushing, often eat sweet or sticky food, resulting in food residues in the decayed parts of the teeth, time is getting longer and longer, the decayed parts will become deeper and deeper, resulting in the occurrence of cavities. Brushing is the best way to prevent tooth decay.