How Do Bone Allografts Regenerate Bone?

utogenous bone is universally considered as the gold standard for grafting procedures, although it presents many limitations such as donor-site morbidity, and postoperative complications such as pain and bleeding. Allogenic bone matrices are excellent alter- natives to autogenous bone grafts because they overcome many of the limitations. This is why they are widely used in the field of dentistry, orthopedics, and craniofacial surgery. Bone allografts are available as mineralized (freeze-dried bone allografts) and demineralized freeze-dried bone allografts and in certain proce dures they show comparable regenerative performance to autoge nous bone grafts, and are well integrated with the host tissues However, the fundamental reasons behind the clinical success of these materials remain unclear It has been observed that demineralized bone matrix could stimulate ectopic bone formationuponits implantationimmuscular tissues. This phenomenon, led to the assumption that specific molecules are responsible for inducing bone formation, later identified as "bone morphogenetic proteins. However recent research has put doubt into this notion. Several studies have shown that the concentration of bone morphogenetic proteins in natural bone grafts is in orders of magnitudes lower than those needed to stimulate new bone formation. Then, why these materials still work so well!