Osteoinduction and its evaluation

Recently, there has been a vast interest in material-induced bone formation or material-directed osteoinduction. This is not only because osteoinduction is becoming a generally accepted phenomenon that can occur with a specific group of biomaterials, but also because of its potential clinical applicability. At this point of research and development, it is possible to induce significant amounts of bone by these so-called instructive materials without the necessity of adding cells and/or growth factors, such as Bone Morphogenetic Proteins (BMPs). This chapter focuses on the phenomenon of osteoinduction in relation to how it was originally demonstrated by Urist for demineralized bone matrix and BMPs and in relation to the current data that have been generated using purely inorganic and synthetic materials. It reviews several possible routes to demonstrate osteoinduction in vitro and in vivo and discusses two mechanisms that may play a role in material-induced bone formation.