Dual-functionalized titanium by ultrafast laser texturing to enhance human gingival fibroblasts adhesion and minimize Porphyromonas gingivalis colonization

Dental implant failure is primarily due to peri-implantitis, a consequence of bacterial penetration causing implant loosening. Beyond supporting the implant, the adhesion of gingival tissues to the surface is essential for its role as a physical barrier to bacteria. Surface nanotextures are widely known to affect wettability, protein adsorption, and cellular and/or bacterial adhesion. In this report, a femtosecond laser (fs-L) was used to design Laser-Induced Periodic Surface Structures (LIPSS) with Infra-Red (IR) or Green lasers on Ti6Al4V. Surface morphology, topography and wettability were characterized. Gingival fibroblasts adhesion was evaluated with sclerometer scratch tests and confirmed by ultrasonic bath cell detachment method. The fs-L texturing increases human gingival cells adhesion compared to polished surface. The adhesion of peri-implantitis associated bacteria was quantified. After 48 h of contact, IR LIPSS show antiadhesive properties for Porphyromonas gingivalis, whereas Green LIPSS, thanks to its smaller spatial period, have limited both Streptococcus mutans and Porphyromonas gingivalis adhesion. Thus, LIPSS generated on Ti6Al4V surfaces, especially Green LIPSS, are identified as having double biological functionality: repellent for bacteria and adhesive for gingival tissues. This study proves that fs-L processing is an innovative tool with potential to enhance implant success paving the way towards dual functionality.