Acceleration of bone-like crystal growth on polarized plasma sprayed HAP in SBF

摘要

Polarizability and Bioactivity of the plasma sprayed Hydroxyapatite (HAp: Ca{sub}10(PO{sub}4){sub}6(OH){sub}2) coatings were estimated from electromagnetism and material science views in this study. The HAp is well known as a highly bioactive ceramic. HAp coatings prepared by plasma spray method were applied to orthopedic and stomatologic implants. We reported that the HAp ceramics were electrically polarizable and that the negatively charged surface enhanced its bioactivity and osteoconductivity. Moreover, it was clarified that the HAp stored electrical charges over 6 months. However, the polarized HAp bulk ceramics cannot be used as implants owing to their low mechanical strength. Thereupon we aimed at the application of the polarization to plasma sprayed HAp. The polarizability of the plasma sprayed HAp was confirmed by thermally stimulated depolarization current measurements. The calculated stored polarization charge was 62.3 μC/cm{sup}2. The surface morphology of polarized plasma sprayed HAp after immersion in simulated body fluid (SBF) showed that crystals growth on the negatively charged surface was accelerated as well as HAp ceramics.