 3. It mediates only the early aspects of bone repair. A variety of treatment modalities including the use of autogenous bone grafts and bone substitutes materials ,guided tissue regeneration GTR with the use of barrier membranes and growth factors have been used to stimulate bone regeneration mechanism.The drawbacks associated with autogenous bone grafts have led to the production of a large number of alternative bone substitute materials. Their biological behavior depends upon their chemical composition and physicochemical structure. Bone grafting materials include autografts, allografts, xenografts and alloplasts. The osteoconductive hydroxyapatite grafting materials have been widely used to enhance new bone regeneration. 