Zirconia has arisen as an alternative to replace titanium in implants due to its chemical stability, mechanical strength, and biocompatibility. The most extensively employed and studied composition for biomedical applications is tetragonal polycrystalline zirconia stabilized with 3 mol% Y2O3 (3Y-TZP), as it exhibits exceptional strength of up to 1200 MPa. However, 3Y-TZP presents only moderate fracture toughness (6 MPa·√m) and is susceptible to low-temperature degradation (LTD), a spontaneous phase transformation that occurs in the presence of water. In this context, Ce-TZP-based nanocomposites have presented an exceptional combination of mechanical strength, toughness, and resistance to LTD. Laser surface treatments have been studied to produce controlled roughness on implants to improve the interaction between tissue and implant. Among the laser techniques, Direct Laser Interference Patterning (DLIP) employs the concept of light interference to create well-defined patterns on the nano- and micrometer range.

This study investigates DLIP as a novel approach for structuring of a Ce-TZP-based nanocomposite. Two infrared laser sources were tested delivering nanosecond (10 ns) and a picosecond (10 ps) pulses. The zirconia nanocomposite sintered discs were subjected to laser patterning using a DLIP system to produce line-like structures with a period of 6.0 μm. The samples were successfully patterned using both ns and ps laser systems. The surface textured by the ns laser was heterogeneous in terms of depth of the fabricated grooves, which presented an average value of 0.8 ± 0.4 μm. Melting and microcracking could also be observed on the surface. On the other hand, the ps laser resulted in a homogeneous surface with an average depth of the fabricated grooves of 2.8 ± 0.8 μm. Regarding the wettability, while the nanosecond increased the surface hydrophilicity, the picosecond laser turned the surface hydrophobic.