Chemistry: Mixture of two phases, hydroxyapatite, HA, and β-tricalcium phosphate. It is a ceramic. Preparation involves the sintering causing the irreversible decomposition of calcium deficient apatites alternatively termed non-stoichiometric apatites or basic calcium phosphate, an example is: Ca10-δ(PO4)6-δ(HPO4)δ(OH)2-δ → (1-δ)Ca10(PO4)6(OH)2 + 3δCa3(PO4)2.
It has been used in implants for petiapical tooth surgery, in orthopedic surgery. It could initiate ectopic osteogenesis.