Teeth are soft when you bite something, it may be the occurrence of tooth abrasion, wedge-shaped defects or cryptocleidosis, specific need to go to the hospital according to the clinical manifestations and X-ray examination to confirm. 1. Tooth abrasion. Improper brushing or bad biting habits such as night grinding can lead to excessive tooth wear, resulting in soreness and discomfort in upper and lower biting and chewing, and in severe cases, endodontic and periapical diseases can also occur. 2. Wedge-shaped defects. Due to the denture repair long-term stress concentration, or to poor brushing habits will cause wedge-shaped defects in the teeth, damage to the dentin layer of the external cold, hot, sweet and sour, resulting in sensitivity. 3. Hidden cracks. Teeth by external impact or bite too hard food will make the teeth occur hidden cracks, lead to the dentin gland to reach the dentin sores will cause biting soft, clinical examination can be seen to lead to hidden crack line. There may be other reasons why the teeth are soft when you bite something, it is likely to be a dental disease, it is recommended to go to the hospital in time for examination and treatment.