It is very likely that the need for bone substitutes will increase in the next decade. The present substitutes are generally bioactive and osteoconductive. Glassy or ceramic materials have been used up to now to act as a guide for bone healing tissue and were shown to admit bone apposition at their surface, probably due to the epitaxial growth of carbonated apatite crystals on it. Different forms of bone substitutes have been developed which do not show exactly the same properties. The reaction of bone tissue against bioactive material debris show major differences from that of polymers or metals. In vitro models were developed to study the interface between bone cells and extracellular matrix, and the surface of bioactive material. Biotechnology makes available some morphgenetic proteins or growth factors in large quantities for combination with osteoconductive material which then can become osteoinductive. Bioartificial bone tissue constituted by a primary osteogenetic cell line immobilised at the surface of osteoconductive materials maade it possible to obtain osteogenic materials. The ideal bone material is still to be engineered. The combination of material sciences and and molecular biology will help to optimise the next generation of material surfaces.