Local induction of calcium phosphate formation on TiO2 coatings on titanium via surface treatment with a CO2 laser.

Sol-gel-derived TiO(2) coatings are known to promote bonelike hydroxyapatite formation on their surfaces in vitro and in vivo. Hydroxyapatite integrates into bone tissue. In some clinical applications, the surface of an implant is simultaneously interfaced with soft and hard tissues, so it should match the properties of both. A new method is introduced for treating the coatings locally in a controlled manner. The local densification of sol-gel-derived titania coatings on titanium substrates with a CO(2) laser was studied in terms of the in vitro calcium phosphate-inducting properties. CO(2)-laser-treated multilayer coatings were compared with furnace-fired coatings prepared with the same recipe and previously shown to be bioactive. Additionally, local areas of furnace-fired multilayer coatings (previously shown to be bioactive in vitro) were further laser-treated to achieve various properties in the same implant. Topological surface properties were examined with atomic force microscopy. The formation of hydroxyapatite was studied with Fourier transform infrared and scanning electron microscopy energy-dispersive X-ray analysis. The results show that calcium phosphate formation can be adjusted locally by laser treatment. Calcium phosphate is a bonelike hydroxyapatite. The local treatment of sol-gel-derived coatings with a CO(2) laser is a promising technique for creating implants with various properties to interface different tissues and a possible way of coating implants that do not tolerate furnace firing.