Resorption of calcium phosphate ceramics of different crystal size

摘要

Hydroxyapatite (HA) has been used successfully for anchorage of endoprostheses. Data regarding the cellular resorption of HA coatings are varying. Until now it is not clear, why some HA materials were degraded by osteoclasts and others were not. In these cases foreign body giant cells (FBGC) were observed. In this study three different HA materials with different crystal sizes were tested. Only microcrystalline HA (crystal size in the range of human bone crystals) was resorbed actively by osteoclasts. Typical lacunae were observed in the surface of the material. If the crystal size of HA was higher (0.1-0.3 mu m or 1-3 mu m) lacunae were not observed any more. In such cases FBGC were detected on implant surfaces. In all three implant types tested bone bonding was observed in a similar amount. The data obtained are important with regard to the design of bioactive materials to special needs, e.g. coatings of endoprostheses.