RESUMO
Electrochemical methods such as voltammetry and chronoamperometry are very useful in the study of biodegradation processes. Voltammetry gives qualitative information on the behaviour of a biomaterial in an electrolytic medium. Accelerated ageing of a metallic biomaterial can be obtained using chronoamperometry. Quantitative information on elements released in a solution is also obtained.
Assuntos
Materiais Biocompatíveis , Teste de Materiais/métodos , Metais , Biodegradação Ambiental , Corrosão , Eletroquímica , Fatores de TempoRESUMO
Most metals used for orthopaedic and stomatology implants and prostheses belong to the families of titanium or nickel-based and cobalt-based superalloys designed for advanced technology industries (e.g. space, aeronautic and nuclear industries). Ideal materials should be as insoluble and biologically compatible as possible. In the present paper the corrosion behaviour of Ni-Cr and Co-Cr alloys in biological media is evaluated through potentiodynamic polarization tests. It is shown that these metals exhibit some minor release of the component elements and degradation products, which may induce cytotoxic and allergic effects. The corrosion resistance of these alloys can be strongly enhanced by hard ceramic coatings deposited by radio-frequency sputtering. The biocompatibility of coated and uncoated metals is compared from differentiated human cell cultures.
