Enhanced Osteoconductivity of Zirconia Implants with One-Step Femtosecond Laser Treatment Through Morphological and Chemical Modifications

Improving surface bioactivity is crucial to acquiring zirconia implants with ideal osteoconductivity. In this work, we enhanced the surface properties of zirconia implants, specifically roughness, hydrophilicity, and osteoconductivity, using a "one-step" femtosecond laser (FSL) treatment in air, deionized water, and sodium hydroxide solution. Zirconia specimens were treated in these media, and their surface morphology, chemical composition, and osteoconductivity were evaluated through various assays. The results showed that FSL treatment successfully created micro/nanoporous structures and increased roughness across all specimens. The liquid media treatment facilitated the grafting of hydroxyl (-OH) groups, significantly improving hydrophilicity. The L-NaOH group exhibited a higher hydroxyl content (28%) compared to the L-Air group (10%), reducing the contact angle significantly. Enhanced osteoblast differentiation and mineralization, along with improved gene expression, were observed in the L-Water and L-NaOH groups. In conclusion, the one-step FSL treatment developed a dual-function bioactive zirconia surface, offering an effective method for the biomedical functionalization of zirconia implants.