Anodized AZ91 magnesium alloy for temporary implants.

CERE; A. GOMEZ SANCHEZ; BALLARRE, JOSEFINA; MERLO JULIETA

sevilla

Congreso; Eurocorr 2019. The European Corrosion Congress.; 2019

SOciedad Europea de Materiales

Magnesium alloys provide potential advantages as a degradable biomaterial for osteosynthesis,because they provide good biocompatibility and high primary stability, while avoiding stressshielding. The primary interest in these alloys is their ability to biodegrade, however, their highcorrosion rate in the physiological medium and the formation of gaseous hydrogen as a corrosionproduct limit their application. The superficial modification of these materials can be thought of asa tool to protect the metal and in turn create a bioactive surface for osseointegration. It is expectedthat the degradation of the metal accompanies the formation of bone tissue and that it maintainsits mechanical properties until it fulfills its function. The corrosion rate of Mg alloys can potentiallybe controlled by changes in metallurgy, microstructure and surface treatments. One of thestrategies of surface modification to promote osseointegration and inhibit corrosion is throughanodizing treatments. These kind of passive layers have been developed and perfected on valvemetals for use in implantology, and it is expected that the generation of the layers in basic mediumon magnesium will allow generating a barrier that in turn is bioactive. The general objective of thiswork is to study the in vitro behavior of an anodized treatment in basic medium on magnesiumalloy AZ91 in simulated physiological medium, for its possible use as a temporary implant. Thechemical, morphological, electrochemical and topological characteristics of samples with andwithout anodizing at constant potential were analyzed in basic medium at different immersion timesin simulated physiological solution. After a day of immersion, the anodized samples denoted thepresence of phosphate compounds related to apatite, being a sign of bioactivity in a short time.The integrity electrochemical tests show that the anodizing process does not induce accelerateddegradation in the samples and inhibits the evolution of hydrogen, thus considering a potentiallyuseful modification for these implants.