Using thermochemical treatment for facilitating apatite formation on Ti-Nb-Sn alloys

Rezende, A. C. S. A.; Wang, Jiale; Li, Yanwen; Carvalho, A. Magnus G.; Souza, Mauro Vinícius de Barros; Santos, Suzana da Costa; Martins, Alessandro; Costa, Ana Maria Duarte Dias; Cremasco, Alessandra; Landers, Richard; Machado, Douglas Silva; Pancotti, A.

doi:10.1007/s10853-019-04281-2

Cited by 5 publications

(2 citation statements)

References 33 publications

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“…25 For example, oxides present in Ti metal facilitated Ti-OH groups. 28,36 Oxides in Ta metal promoted Ta OH, 7,37,38 like what is expected for the oxides identified here, Ta The biological assay in animals showed no harmful effect observed in both conditions analyzed, which means that the alloy can be used safely. Although this alloy has been completed unedited, Deng et al 39 have demonstrated that cobalt-based alloys are safe for in vivo use.…”

Section: Discussionsupporting

confidence: 80%

“…Literature reports that functional groups such as TaOH, SiOH, TiOH, ZrOH, NbOH, COOH, and PO 4 H 2 can induce apatite growing due to its specific structure and negative charges that favor amorphous calcium formation, which turns into HA 25 . For example, oxides present in Ti metal facilitated Ti‐OH groups 28,36 . Oxides in Ta metal promoted TaOH, 7,37,38 like what is expected for the oxides identified here, Ta 1.1 O 1.05 and Ca 2 Ta 2 O 7 .…”

Section: Discussionsupporting

confidence: 74%

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Physical, morphological and bioactive properties of Co–Cr–W–Ta alloys: Influence of insertion of tantalum and surface thermochemical treatment on bioactivity

et al. 2023

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The development of bioactivity in bioinert metallic alloys is a field of interest aiming to improve some aspects of these materials for implant applications. New Co 63 Cr 28 W 9-x Ta x alloys with different Ta concentrations (x = 0, 2, 4, 6, and 9% w/w) were synthesized in the work reported here. The alloys were characterized by x-ray diffraction, volumetric density, Vickers microhardness, atomic force microscopy, scanning electron microscopy (SEM), and energy-dispersion x-ray spectroscopy (EDS). Bioactivity properties were evaluated by in vitro tests with simulated body fluid (SBF). In vivo assays were performed to assess biocompatibility. The influence of surface thermochemical treatment and Ta insertion on the bioactive properties of the alloys was investigated. The results showed that the alloy structure comprises εCo and αCo phases, with cobalt as a matrix with Cr, W, and Ta as a solid solution. TaCo 2 phase is observed in the alloys with 4, 6, and 9% w/w of Ta, and its amount increase as Ta concentration increases. Volumetric density is reduced (from 8.78 ± 0.06 to 8.56 ± 0.09 g/cm 3 ) as Ta concentration increases (from 0% to 9% w/w) mainly due to the lower density of the tantalum compared to the tungsten metal. On the other hand, the TaCo 2 phase contributes to the increase of Vickers's hardness by $17.6% for the alloy with 9% Ta (394.7 ± 8.1 HV) compared with Co 63 Cr 28 W 9 (336 ± 5 HV). The topographic analysis showed increased roughness and adhesion due to the nucleation of Ta 1.1 O 1.05 and Ca 2 Ta 2 O 7 crystals after surface thermochemical treatment. The roughness and adhesion increase from 16.9 ± 0.6 nm and 8.3 ± 1.8 nN (untreated surface) to 255.7 ± 17.7 nm and 24.1 ± 12.6 nN (treated surface), respectively, for the Co 63 Cr 28 Ta 9 alloy. These results suggest that thermochemical treatment provides surface conditions favorable to hydroxyapatite (HA) nucleation. The SEM and EDS data showed the nucleation of spongy structures, consistent with HA, composed mainly of Ca and P, indicating that oxides tantalum promoted a bioactive response on the sample's surface. The biological assay corroborated the alloy's safety and applicability, highlighting its potential in biomedical application since no harmful effects were observed.

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