@conference{
author = "Cvijović-Alagić, Ivana and Laketić, Slađana and Momčilović, M. and Ciganović, Jovan and Veljović, Đorđe and Bajat, Jelena and Kojić, Vesna and Rakin, Marko",
year = "2023",
abstract = "Modern hard tissue replacements, used in orthopedic and dental surgery, are most commonly produced using commercially pure titanium (CP-Ti) and the (α+β) Ti-based alloys since their biomechanical compatibility is superior in comparison to other metallic biomaterials. However, these materials are still unable to meet all implantation requirements primarily due to their somewhat limited resistance to degradation in harsh bio-environment and/or presence of cytotoxic elements in their composition that can cause adverse health effects. Therefore, the potential biomedical application of the β-type Ti alloys, which contain non-toxic elements, is considered since these alloys can exhibit lower elastic modulus and improved biocompatibility compared with other Ti-based materials. The β-type Ti-45Nb (wt%) alloy shows significant potential for application as hard tissue implant material. Nevertheless, an additional improvement of its response in the bio-environment is necessary to maximize its medical applicability. Modification of the alloy’s microstructural and surface characteristics through the careful selection of the appropriate processing parameters can ensure the obtainment of favorable alloy biocompatible properties. High-pressure torsion (HPT), as a processing method for the obtainment of ultra-fine grained (UFG) microstructure with higher compatibility with biological systems, and laser surface scanning, as an easy-to-apply surface modification technique for the obtainment of developed bio-active surface, are singled-out as potential methods for the attainment of more durable orthopedic and dental implants. Having all this in mind, the present research aimed to attain improved corrosive and biocompatible response of the Ti-45Nb alloy in simulated physiological conditions through the alloy grain refinement and the formation of protective surface scales by the alloy combined HPT and laser irradiation processing. For that purpose, the alloy microstructural, electrochemical, and in vitro testing were conducted before and after its additional processing. Attained results indicated that the achieved grain size reduction from 2.76 µm to ~200 nm during HPT processing and the appearance of laser-induced morphologically altered and highly oxidized surface led to the significant improvement of the alloy corrosion resistance and the cellsimplant interaction. Moreover, an additional increase of the laser pulse energy from 5 mJ to 15 mJ during the alloy irradiation in air led to an increase in oxygen content at the alloy surface from 13.64% to 23.89% accompanied by an increase of cell viability from excellent 127.18% to superior 134.42%. Furthermore, as a result of the controlled alloy microstructural and surface morphological and chemical modifications, the formation of a thick, compact and protective bi-modal external scale, composed of mixed Ti- and Nboxides, was enabled in the simulated body conditions. Presence of this surface oxide scale, which consists of inner barrier and outer porous layer, enhanced the alloy’s resistance to corrosion deterioration and simultaneously boosted the cell viability and proliferation. Results of the present study showed that the additional HPT and laser surface processing can be successfully utilized to improve the biometallic’s response to a bio-environment",
publisher = "Slovak Republic : Institute of Inorganic Chemistry, SAS",
journal = "EngCer 2023 : The Advanced Research Workshop: Engineering Ceramics",
title = "Laser-modified Ti-45Nb alloy’s response to bio-environment",
pages = "12",
url = "https://hdl.handle.net/21.15107/rcub_vinar_11343"
}
