Nanostructured surfaces

Femtosecond laser surface micro- and nano-texturing of metals, alloys and ceramics perspective for biomedical applications
Berezovska N.I.1, Dmitruk I.M.1, Kolodka R.S.1, Dmytruk A.M.2, Blonskiy I.V.2, Mishchenko O.M.3, Pogorielov M.V.4
1 Physics Faculty, Taras Shevchenko National University of Kyiv. Volodymyrska Street, 64/13, Kyiv-01601, Ukraine. 
E-mail: n_berezovska@univ.kiev.ua
2 Photon Processes Department, Institute of Physics of the NAS of Ukraine. Prospect Nauki, 46, Kyiv-03039, Ukraine.
3 Medical Faculty No. 3, Zaporizhzhia State Medical University. Maiakovskyi Prospect, 26, Zaporizhzhia-69035, Ukraine.
4 Department of Public Health, Medical Institute of Sumy State University. Pratsi Street, 3, Sumy-40000, Ukraine.

Direct surface modification of different materials using powerful ultra-short laser pulses attracts more attention due to the various perspective applications. Laser treatment is one of the best techniques of micro- and nanotexturing of the dental implants surfaces which can improve the adhesion of living tissues [1].
Laser-induced surface structures on titanium (Ti), dental implants of Ti-based alloys and zirconia ceramics have been obtained by the irradiation of the initial surface with Ti:sapphire femtosecond laser. The influence of laser radiation parameters (power density, pulse duration, wavelength, polarization) on the samples surface morphology have been studied. The most qualitative structuring of implant specimens has been observed at a higher irradiation power density at a higher scanning speed. An increase of the laser power density also contributes to the uniformity of the structure within the laser beam spot on the surface, which minimizes the inhomogeneities at the junctures of strips of consecutive laser beam passes. It has been discovered that additional structures of irregular round shape on the surface of implants of Ti-based alloys, which are considerated as disadvantage for increasing biocompatibility, are caused by the formation of oxides on the surface during the laser processing.

1.	Liu X., Chu P. K., Ding C. Surface modification of titanium, titanium alloys, and related materials for biomedical applications // Mater Sci Eng R Rep.-2004.– 47.-P. 49-121.