Influence of Sterilization with γ-Irradiation in the Degradation of Plasma Sprayed Hydroxyapatite Coatings


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The influence of sterilization with γ-irradiation in the properties of plasma sprayed hydroxyapatite (HAp) coatings used for medical implants is investigated in this work. HAp coatings were applied on titanium alloy substrates by plasma spraying and then submitted to 1 and 10 cycles of sterilization with γ-irradiation. As-applied HAp coatings were used as control samples. Afterwards, the modifications on the samples, induced by the irradiation process, were evaluated by X-ray diffraction and X-ray photoelectron spectroscopy (XPS). Water contact angle measurements as well as adhesion tests were also carried out in order to evaluate the influence of the irradiation process on the wettability and mechanical behaviour of the HAp coatings. No microstructural modifications were detected by X-ray diffraction after sterilization. However, the results show that sterilization with γ-irradiation originates modifications of the surface of HAp, as detected by a change of color of the coatings and by the XPS analysis. Nevertheless, these modifications do not result in significant changes in the wettability and mechanical behaviour of the HAp coatings.



Materials Science Forum (Volumes 514-516)

Edited by:

Paula Maria Vilarinho




T. Costa et al., "Influence of Sterilization with γ-Irradiation in the Degradation of Plasma Sprayed Hydroxyapatite Coatings", Materials Science Forum, Vols. 514-516, pp. 1054-1058, 2006

Online since:

May 2006




[1] J. Suwanprateeb, K. E. Tanner, S. Turner and W. Bonfield, Influence of sterilization by γirradiation and of thermal annealling on creep of hydroxyapatite reinforced polyethylene composites, Journal of Biomedical Materials Research, 39 (1), 16-22 (1998).


[2] G. Gillman, Sterilization can change properties of bioceramics, Mat. -wiss. u. werkstofftech., 34 198-2002 (2003).

[3] A. P. Serro and B. Saramago, Influence of sterilization on the mineralization of titanium implants induced by incubation in various biological model fluids, Biomaterials, 24, 4749-4760 (2003).


[4] M. Takeshi, Y. Miyamoto, Y. Momota, T. Yuasa, S. Tatehara, M. Nagayama and K. Ishikawa, Effect of various sterilization methods on the setting and mechanical properties of apatite cement, J. of Biomedical Materials Research, Part B - Applied Biomaterials, 69 (1), 58-63 (2004).


[5] Standard Test Method for Tension Testing of Calcium Phosphate and Metal Coatings, Standard ASTM F1147-99, Book of Standards Volume 13. 01 (1999).

[6] K. A. Gross, W. Walsh and E. Swarts, Analysis of retrieved hydroxyapatite-coated hip prostheses, J. of Thermal Spray Technology, 13 (2), 190-199 (2004).


[7] Implants for surgery - hydroxyapatite - part 2: coatings of hydroxyapatite, Standard ISO-137792 (2000).