Application of Concentrated Growth Factors in Alveolar Ridge Preservation

Inclusion Criteria: Voluntarily participate in this trial and sign a written informed consent; Patients aged 25 ≤ age ≤ 45 years; The combination of intraoral and imaging examinations confirms that the affected tooth has no preservation value, requires tooth extraction, and the patient is willing to use site preservation; No progressive periodontal disease or acute apical periodontitis in the affected teeth; No long-term history of oral bisphosphonates; Non smoking patients； No systemic diseases such as diabetes and hypertension. Exclusion Criteria: Patients who have difficulty tolerating surgery; Patients under 25 years old or above 45 years old; The whole body is accompanied by hypertension, diabetes and other serious systemic diseases, which need to be controlled by drugs; Patients who take oral medication that affects bone metabolism for at least one month due to the need for disease treatment; Patients who take medication that may affect platelet function was used within 3 months due to the need for disease treatment; Patients unable to undergo X-ray imaging examination due to pregnancy or preparation after site preservation surgery; Patients who Smoke; The apical and periodontal inflammation is in the acute phase (purulent phase) Regular follow-up or follow-up for more than 6 months is not allowed