The complete healing of the wound after tooth extraction is usually within 3 to 6 months, but the healing of the gingiva on the surface of the tooth extraction wound is usually basically completed in about 20 days, and the complete healing is divided into five stages. 1. Formation of blood clot after tooth extraction. In the immediate after extraction, usually 15 to 30 minutes after the bleeding stops, the formation of blood clot closed extraction wound. 2. Formation of granulation tissue by mechanization of the blood clot. In about 24 hours to seven days after tooth extraction, the blood clot gradually forms vascular buds that are replaced by granulation tissue. 3. Connective and epithelial tissues replace the granulation tissue. Three to four days after tooth extraction, mature step tissue begins to replace the granulation tissue, which is basically completed in about 20 days, and new bone begins to form to fill the extraction socket five to eight days after the operation. 4. Primary fibrous bone replaces connective tissue. One month to three months after surgery, the new bone completely replaces the connective tissue. 5. Mature bone tissue replaces immature bone tissue. About three months after extraction, mature bone tissue gradually replaces immature bone, and the shape of the alveolar bone tends to stabilize. The incision after removal of stitches usually heals completely in about three months, but the time may be extended depending on the individual’s physical condition.