Femtosecond laser-induced periodic surface microstructure on dental zirconia ceramic

The inert and high-strength of zirconia ceramic make it a big challenge to develop simple and reliable methods for increasing surface roughness with controlled morphologies. This study investigated the suitability of femtosecond laser for surface modification of zirconia. The laser pulse energies were set at 180 μJ and 90 μJ respectively, with pulse duration of 35 fs, a repetition rate of 2 kHz, and wave length at 800 nm. Scanning electron microscopy observation of well-distributed periodic and cyclic microstructure revealed the effectiveness of femtosecond laser ablation and minimal collateral damage of the surface. Laser scanning confocal microscope analysis showed femtosecond laser ablation increased the surface roughness significantly, and the depth of the microstructure was related to the pulse energy of the femtosecond laser. X-ray diffraction showed that the original predominant tetragonal phase of zirconia was preserved in the crystalline structure induced by femtosecond laser processing. The obtained results suggest that femtosecond laser treatment offers a fast and promising approach to introduce controlled topography at the micrometric and sub-micrometric scale.