Abstract
To evaluate the biocompatibility of refractory metals in group IVa and Va, these metals were implanted in rats, then subjected to metal surface roughness test by atomic force microscopy, histological examination by optical microscopy, histomorphometry by image analyzer, mapping of metal dissolution by X-ray scanning analytical microscopy and EPMA, observation of osteogenesis by confocal laser scanning microscopy (CLSM) and highly sensitive analysis by ICP. None of metals except vanadium showed any inflammatory response. The amount of new bone changed little and the bone-metal contact increased markedly from the 2nd to 4th week after implantation. The image of fluorescent labeling by CLSM and calcium enrichment by EPMA revealed that remodeling and calcification proceeded. While vanadium showed a suppressive effect in bone formation. ICP showed vanadium dissolved after immersion in simulated body fluid. These results suggest that zirconium, hafnium, niobium and tantalum have good biocompatibility equivalent to that of titanium.
