Bone substitute material

A biphasic calcium phosphate/hydroxyapatite (CAP/HAP) bone substitute material comprising a sintered CAP core and having its total external surface covered by at least one closed epitactically grown layer of nanocrystalline HAP, whereby the epitactically grown nanocrystals have the same size and morphology as human bone mineral, wherein the closed epitactically grown layer of nanocrystalline HAP is transformed from the CAP on the external surface of the sintered CAP core such that the closed epitactically grown layer of nanocrystalline HAP has a non-homogeneous external surface comprising individual clusters of flat crystal platelets consisting of epitactically grown HAP nanocrystals and coarse areas between the individual clusters consisting of platelets of HAP nanocrystals with individual platelet sizes of 0.2 to 5 μm as measured by SEM, whereby the percentage of the coarse areas between the individual clusters as measured by SEM is at least 20% of the total surface of the CAP/HAP bone substitute material.