Growth of Calcium Phosphate Coating on Ti-7.5Mo Alloy after Anodic Oxidation

Abstract:

Titanium and its alloys are widely used as biomaterials due to their mechanical, chemical and biological properties. To enhance the biocompatibility of titanium alloys, various surface treatments have been proposed. In particular, the formation of titanium oxide nanotubes layers has been extensively examined. Among the various materials for implants, calcium phosphates and hydroxyapatite are widely used clinically. In this work, titanium nanotubes were fabricated on the surface of Ti-7.5Mo alloy by anodization. The samples were anodized for 20 V in an electrolyte containing glycerol in combination with ammonium fluoride (NH₄F, 0.25%), and the anodization time was 24 h. After being anodized, specimens were heat treated at 450 °C and 600°C for 1 h to crystallize the amorphous TiO₂ nanotubes and then treated with NaOH solution to make them bioactive, to induce growth of calcium phosphate in a simulated body fluid. Surface morphology and coating chemistry were obtained respectively using, field-emission scanning electron microscopy (FEG-SEM), AFM and X-ray diffraction (XRD). It was shown that the presence of titanium nanotubes induces the growth of a sodium titanate nanolayer. During the subsequent in-vitro immersion in a simulated body fluid, the sodium titanate nanolayer induced the nucleation and growth of nanodimensioned calcium phosphate. It was possible to observe the formation of TiO₂ nanotubes on the surface of Ti-7.5Mo. Calcium phosphate coating was greater in the samples with larger nanotube diameter. These findings represent a simple surface treatment for Ti-7.5Mo alloy that has high potential for biomedical applications.

• Periodical: Defect and Diffusion Forum (Volumes 334-335)
• Pages: 297-302
• DOI: https://doi.org/10.4028/www.scientific.net/DDF.334-335.297
• Online since: February 2013
• Authors: A.L.A. Escada, João Paulo Barros Machado, Roberto Zenhei Nakazato, Ana Paula Rosifini Alves Claro
• Keywords: Calcium Phosphate, Nanotubes TiO₂, Titanium Alloy

References

[1] J. Gerber, D. Wenaweser, J. Heutz-Mayfield, N.P. Lang and G. R Persson: Clin. Oral Impl. Res. Vol. 17 (2006), p.1.

[2] M.M. Bornstein, B. Schmid, A. Lussi, V.C. Belser, D. Buser: Clin. Oral Impl. Res. Vol. 16 (2005), p.631.

[3] P. Peng, S. Kumar, N.H. Voelcker, R. St.E. Szili, C. Smart, H.J. Griesser: J. Biomed. Mater. Res. A Vol. 76 (2006), p.347.

[4] S. Kumar, T. S. N. Sankara Narayanan: Journal of Dentistry Vol. 36 (2008), p.500.

[5] M. Uchida, H.M. Kim, T. Kokubo, S. Fujibayashi, T. Nakamura: J. Biomed. Mater. Res. Vol. 64 (2003), p.164.

[6] S. Oh, S. Jin: Mater. Sci. Eng. C Vol. 26 (2006), p.1301.

[7] H. Tsuchiya, J.M. Macak, L. Müller, J. Kunze, F. Müller, P. Greil, S. Virtanen, P. Schmuki: J. Biomed. Mater. Res. A Vol. 77 (2006), p.534.

DOI: 10.1002/jbm.a.30677

[8] B.B. Lakshmi, C.J. Patrissi, C.R. Martin: Chem. Mater. Vol. 9 (1997), p.2544.

[9] Z. Miao, D. Xu, J. Ouyang, G. Guo, X. Zhao, Y. Tang: Nano Lett. Vol. 2 (2002), p.717.

[10] J.M. Macak, K. Sirotna, P. Schmuki: Electrochim. Acta Vol. 50 (2005), p.3679.

[11] S. -H. Oh, R.R. Finõnes, C. Daraio, L. -H. Chen, S. Jin: Biomaterials Vol. 26 (2005), p.4938.

[12] W.F. Ho, C.H. Lai, H.C. Hsu, S.C. Wu: Surface Coatings Technol. Vol. 203 (2009), p.3142.

[13] F. Barrère, M. E. Snel, C. A. van Blitterswijk, K. Groot, P. Layrolle: Biomaterials Vol. 25 (2004), p.2901.

[14] K.O. Varghese, D. Gong, M. Paulose, K.G. Ong, E.C. Dickey, A.C. Grimes: Advanced Materials Vol. 15 (2003), p.624.

[15] J. Yu, B. Wang. Applied Catalysis B: Environmental Vol. 94 (2010), p.295.