Calcium phosphate ceramics are used in bone surgery under different forms: dense or porous ceramic s as bone substitute, thin ceramic coatings on metallic implants as an osseointegration enhancer. Their degradation depends on their physico-chemical properties and particularly on their chemical composition. Natural calcium phosphates of bone are degraded by mononuclear or multinuclear cells and the extracellular matrix induces the differentiation of the degrading-cells. Hydroxyapatite, which is one of the most used calcium phosphates , is known as a low degradation material. However, the histological analysis of implanted HA-materials both in animals and in humans showed that a cellular degradation took place on the surface of the material.
Frayssinet, P.; Rouquet, N.; Tourenne, F.; Fages, J.; Hardy, D.; and Bonel, G.
"Cell-Degradation of Calcium Phosphate Ceramics,"
Cells and Materials: Vol. 3
, Article 6.
Available at: http://digitalcommons.usu.edu/cellsandmaterials/vol3/iss4/6