INTEMA   05428
INSTITUTO DE INVESTIGACIONES EN CIENCIA Y TECNOLOGIA DE MATERIALES
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
MAGNESIUM ALLOYS FOR ORTHOPAEDIC TERMPORARY IMPLANTS: SURFACE AND ELECTROCHEMICAL PERFORMANCE IN VITRO
Autor/es:
SHEILA OMAR; JOSEFINA BALLARRE; CERE, SILVIA
Lugar:
Foz do Iguazu
Reunión:
Congreso; 9no Congreso Latinoamericano de Organos Artificiales y Biomateriales COLAOB; 2016
Institución organizadora:
SLABO
Resumen:
A biodegradable implant is a material that can gradually dissolved and adsorbed after implanting. Compared with a traditional permanent implant, a biodegradable material will not cause permanent physical irritation or chronic inflammatory discomfort, and also is it thought to have a performance related with bone strength and to help to bone healing. Magnesium is potentially a good temporary implant material for its non-toxicity to the human body. Mg2+ is present in large amount in the human body and involved in many metabolic reactions and biological mechanisms. Since rapid corrosion is almost an intrinsic response of magnesium to a chloride containing solution like the human body fluid or plasma, it is possible to utilize the low corrosion performance of magnesium to be a bio-degradable implant material. The aim of this work is to characterize the in vitro performance of two used Mg alloys (ASTM AZ31 and AZ91) with different amount of alloying elements, as bio-degradable transitory implants.This work presents the in vitro analysis of two used Mg alloys for temporary implants in terms of superficial deposits and corrosion products, and electrochemical behavior. The corrosion products are analyzed with Raman spectroscopy and UV-Vis techniques. Electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization curves are used to evaluate the degradation of the materials with immersion time. The samples are immersed in Hanks solution for a period of 0 to 28hs, and for 30 days, and the tests are carried out at room temperature (25 ºC) and at 37 ºC. The effect of temperature is evaluated together with the superficial oxide stabilization with the immersion time by EIS and differential reflectance. The AZ31 and AZ91 alloys present variable total resistance of the system during the first 24hs of immersion, being stable the surface after this period of time. The oxo-hydroxides present in both Mg alloys are characterized by Raman and UV-vis spectroscopy, corroborating that after 24 hs of immersion in Hanks solution, the surface present a reproducible composition. As expected, the deterioration of the alloys is faster at 37 ºC than at room temperature.