<qa>  What is the gold standard still widely used when a bone graft is required?When a bone graft is required the gold standard still widely used is autogenous cancellous bone. However, the graft harvesting procedure is invasive and increases patient morbidity lengthened surgical procedure, increased risk of infection. Moreover, the availability of autologous grafts is limited, especially in elderly patients. This has been the rationale for studying alternative sources for bone grafts. 