Abstract
The biocompatibility of pure nickel and Ni-Ta binary alloy were histopathologically and chemically evaluated in rat subcutaneous tissue.The tissue around the pure nickel showed necrotic-like or eosinophilic amorphous masses with severe inflammatory changes.A large amount of Ni2+ was detected in the subcutaneous tissue around the nickel metal in all of the experimental animals.The tissue around Ni-10wt% Ta, Ni-20wt% Ta and Ni-30wt% Ta was formed by fine fibrous tissue layers without inflammatory cells infiltration, and granular foci showing good biocompatibility.However, a small amount of Ni2+ was detected in the tissue around these alloys.These findings indicate that Ni-Ta alloys corrode and that nickel is released as Ni2+ or nickel compounds and remains in the tissue without destroying the tissue.The experiments show that nickel, which causes serious inflammation in the tissue, is released from Ni-Ta alloys and remains in the surrounding tissue.Even when there is no evidence of any cellular changes in the surrounding tissue, small amounts of Ni2+ can be detected.
