Effect of Collagen Versus PRF on BMA Osteogenic Potential

Inclusion Criteria: * Patients who has as deficient as 4 mm vertical bone height in posterior maxilla that need bone augmentation before delayed implant placement. * Highly motivated patients * Age more than 18 years Exclusion Criteria: * Patients suffering from any systemic disease or those under any medication that may interfere with normal bone healing. * Patients suffering from any sinus pathosis. * Patients with conditions that could potentially compromise Bone Marrow ( BM)quality, including history of hematologic malignancy, current chemotherapy, BM suppressive and anti-platelet medications, previous BM Aspiration, or acute illness. * Heavy smoker (\> 20 cigarettes daily)