After tooth extraction, the soft tissue wound on the surface of the extraction wound usually heals in 5-7 days. About 30 minutes after tooth extraction, blood clotting and formation of blood clot will occur in the extraction wound. About 24 hours after the extraction, the clot begins to mechanize and gradually forms granulation tissue. In about 20 days, the granulation tissue is replaced by more mature fibrous connective tissue, while resorption and reconstruction of the alveolar bone occurs. In about three months, all bone tissue is formed in the alveolar socket, but at this time it is immature bone tissue with low bone density. About 6 months after tooth extraction, the bone reconstruction is basically completed, and the immature bone tissue is gradually replaced by the mature bone tissue, showing the normal bone tissue shape. Only at this time is the extraction wound completely healed.