COMPARATIVE BIOLOGICAL PROPERTIES OF HA PLASMA-SPRAYED COATINGS HAVING DIFFERENT CRYSTALLINITIES

Plasma-sprayed HA-coatings used for orthopaedic surgery can contain di fferent percentages of crystalline phase. The influence of the amount of crystalline and amorphous phase on the biological properties of coa tings is not known. The aim of this study is to determine the effect o f this coating characteristic on mammalian cell functions in vitro. It appears that 100% crystalline coatings have an inhibiting effect on c ell proliferation and on alkaline phosphatase activity. A direct conta ct of the cells with the material is necessary to obtain this effect. The material evolves during the period of culture. Poorly crystalline coatings dissolve during the period of culture and the roughness param eters change during the same period.