Recubrimientos de Hidroxiapatita Nanocristalina – Preparación, Caracterización y Evaluación de la Bioactividad

Abstract

The coating of metallic alloys with bioactive ceramics aims to accelerate bone formation around implant, contributing to its fixation. In this paper, the deposition of bioactive hydroxyapatite ceramic by sol-gel method on Ti-6Al-4V alloy sheets was studied. Coatings prepared from hydroxyapatite sol have been accomplished by dip-coating technique on non-toxic Ti-6Al-4V alloy for biomedical applications. The coating layer was characterized by X-ray diffraction provided valuable information about the phase transformation, identification of the phases developed and degree of crystallinity. Scanning electron microscopy was applied to study the surface morphology and coating adhesion to substrate was evaluated by shear testing (ASTM F 1044-05). The obtained results show that all the prepared samples are ceramic nanopowders with crystal structure and composition like hydroxyapatite, with small deviations from the one present in the human bone. The corrosion behavior of the resulting hydroxyapatite coatings in a simulated body fluid (SBF) was studied by electrochemical impedance spectroscopy. The hydroxyapatite coated Ti-6Al-4V alloy displayed excellent bioactivity when soaked in the SBF and acceptable corrosion protection behavior. The citocompatibility test according to ISO 10993-5 standard shows that sol-gel coating did not provoke cell dead.