Osteoinductive properties of micro macroporous biphasic calcium phosphate bioceramics

We have developed 17 years ago, with the collaboration of Lynch, Nery, and Legeros in USA, a bioactive concept based on biphasic calcium phosphate ceramics (BCP). The concept is determined by an optimum balance of the more stable phase of HA and more soluble TCP. The material is soluble and gradually dissolves in the body, seeding new bone formation as it releases calcium and phosphate ions into the biological medium. The bioactive concept based on the dissolution/transformation processes of HA and TCP with a specific microstructure (micropore) and macrostructure (mesopores and macropores) represents a dynamic process, including physico-chemical processes, crystal/proteins interactions, cells and tissue colonization, bone remodelling, finally contributing to ingrowth at the expense of the MBCP. The microstructure of such material is achieved with low temperature sintering conditions preserving the microstructure. The material has shown osteoconductive properties largely reported in the literature, but its osteionductive properties have not been explored and documented for such bioceramics (Triosite(R) Zimmer). This paper presents retrospectives series of animal data (rats, rabbits, dogs, cats) demonstrating that promotion of the mineralization into micropores occurred simultaneously with osteoid and bone ingrowth into mesopores and macropores in non bony sites.