Zirconia stabilized with 3 mol% Y2O3 (3Y-TZP) has emerged as a promising biomaterial due to its exceptional mechanical properties (flexural strength up to 1200 MPa), chemical stability and biocompatibility. To further improve the surface properties of zirconia implants, laser texturing processes are being explored to create controlled roughness on the surface of biomaterials aiming to improve the interaction between implant and bone. Among the laser techniques, Direct Laser Interference Patterning (DLIP) is a fast and accurate method that uses the interference of multiple laser beams to create well-defined micro- and nano-patterns on the surface of implants. However, laser-induced heat can lead to a resolidification layer, crack formation, and phase transformation, ultimately compromising the material strength.

This work aims to study the effect of DLIP with a nanosecond pulsed laser on the morphology, microstructure, wettability and mechanical strength of zirconia 3Y-TZP. The zirconia sintered discs were subjected to DLIP equipped with a nanosecond laser source (10 ns) to produce a line-like pattern with a periodicity of 6.0 μm. The samples were successfully textured, resulting in grooves with an average depth of approximately 0.8 μm. However, defects related to the thermal mechanism of ablation, such as resolidification layer and microcracking, could be observed in the samples. In addition, the laser texturing increased the wettability of the samples, which showed a water contact angle of 90.4 ± 2.0° for the control (polished) group and decreased to 58.9 ± 15.5° after the patterning. Although a small decrease in the flexural strength of zirconia was recorded after the laser texturing, from 1158 ± 185 MPa to 1099 ± 76 MPa, it is not statistically significant. Furthermore, the smaller standard deviation indicates higher reliability of the textured samples.