Evaluation of biomimetic coatings on femtosecond laser treated alumina and alumina-zirconia composite surfaces

Abstract

The effect of texturing Al2O3 and Al2O3/ZrO2 surfaces using femtosecond laser has been evaluated in terms of the roughness, wettability and microstructure of the substrate to increase growth efficiency and adhesion of hydroxyapatite. Femtosecond laser treatment of these materials causes phase transformation from alpha-alumina to gamma-alumina. Heat effects during femtosecond laser treatment causes the grains to be in the nanometer scale. Without heat effects, the grains are in the micrometer scale. The use of femtosecond laser permits control of the surface roughness of the alumina specimens. The higher the femtosecond laser energy, the higher is the wettability of the specimen and the total surface energy. Specimens with laser textured surfaces upon immersion in 1.5 SBF for 6 and 15 days revealed apatite layers well bonded to the substrate and without detachment. The adhesion of apatite to surfaces of specimens that were not textured with femtosecond laser was inadequate.