[Physicochemical characterization and histological bone-formability evaluation of electrically polarized hydroxyapatite].
Acceleration and deceleration of bone-like crystal growth on electrically polarized hydroxyapatite ceramics are induced by their surface changes, as recently reported by Yamashita, et al. In this study, new-bone-forming ability of electrically polarized hydroxyapatite was physicochemically characterized and histologically evaluated using femora and tibiae of rabbits. The electrical polarizability of hydroxyapatite was demonstrated by thermally stimulated current measurements. No significant difference between polarized and non-polarized hydroxyapatite was recognized by IR spectroscopy and X-ray diffractometry. A negatively charged hydroxyapatite surface exhibited osteogenesis with direct bone contacting in early stage. A positively charged surface resulted in a small amount of bone formation on the surface. On the contrary, in the zone isolated by fibrous layer, a large volume of bone newly formed. It is useful that the outstanding bone-formability in the early stage on a negatively charged surface implies more rigid initial fixation in orthopedic and dental fields. Positively charged surfaces have a new-bone-conducting property that acts over a long distance, and the possibility of controlling osteogenesis.
Kobayashi
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Department of Inorganic Materials, Tokyo Medical and Dental University.
D000818:Animals; D004558:Electric Stimulation; D006882:Hydroxyapatites / Q000494:pharmacology*; D010012:Osteogenesis / Q000187:drug effects*; D011817:Rabbits
D006882:Hydroxyapatites