Whether tooth extraction is good or not cannot be generalized. When the prognosis is poor, obviously loose, and the residual root and crown cannot be repaired, timely extraction can effectively preserve the bone volume and avoid resorption and atrophy of the alveolar bone, which has certain benefits. If the teeth that can be preserved are directly extracted, the opportunity to use the residual roots for restoration is lost, causing a decrease in chewing function. Rough extractions may damage the alveolar bone, causing bone fractures, swelling and pain. Sometimes tooth extraction can cause severe bacterial infection, resulting in swelling of the jaw and face, generalized fever, and even damage to the inferior alveolar nerve, with irreversible numbness and motor impairment.