Inclusion Criteria:  Cooperative patients with good oral hygiene. Patients having a history of mandibular premolars indicated for extraction and immediate replacement.  Exclusion Criteria:  Heavy smokers. Parafunctional occlusal habits. Uncontrolled diabetes. History of chemotherapy or radiotherapy. Hematological disorders that prevent either implantation or centrifugation. Pregnancy. The nee¬d for additional augmentation or previous augmentation of the same region. Chronic periapical pathology