**5. Bone graft substitute**

The bone graft substitute is basically a synthetic inorganic or biologically organic combination, which guides to stimulate bone healing and fill bone defects. A good bone grafting substitute should have low immunogenicity and higher biocompatibility, and at the same time, it should be able to mold itself according to grafting needs. Bone grafts find application and are primarily used for linkage and splintage and help in promoting ontogenesis. In the case of linkage, bone grafts are utilized for filling cavities or defects in bone, replacement of crushed bone, and arthrodesis. While splintage-related grafting protocols are utilized for nonunion bone deformities and arthrodesis [29]. An understanding of bone formation, process of osteogenesis, osteoinduction, and osteoconduction is a prerequisite for appreciating the biology of graft substitution. The type of graft used and its physicochemical properties play an important role in its success. On a global scale, around 2.2 million graft substitutions are performed annually with 9 out of 10 falling under the category of allograft or autografts. This bone grafting procedure typically follows the multistep cascade:


*Application of Bone Substitutes and Its Future Prospective in Regenerative Medicine DOI: http://dx.doi.org/10.5772/intechopen.85092* 

**Figure 2.**  *Schematic representation shows the process of bone graft substitues.* 

Broadly, the substitute materials can be categorized as natural and synthetic grafts. Under the natural grafting substitutes fall autografts and allografts.
