Surface texturing of Ti6Al4V alloy using femtosecond laser for superior antibacterial performance

Titanium and its alloys are the most widely used implant materials in dental and orthopedic fields. However, bacterial infections occurring during implantation lead to implant failure in most of the cases. In this work, the authors have surface modified Ti6Al4V alloy using a femtosecond laser and achieved antibacterial behavior of such laser treated samples. Laser induced microstructure was observed on the Ti6Al4V alloy surface post laser treatment. Generation of various suboxide phases of titanium dioxide was detected on laser treated samples using x-ray diffraction and x-ray photoelectron spectroscopy. Wettability of Ti6Al4V alloy changed significantly after surface treatment with the laser. Adhesion and growth of two gram positive bacteria, Staphylococcus aureus and Streptococcus mutans, and one gram negative bacteria, Pseudomonas aeruginosa, have been explored on pristine as well as on laser textured Ti6Al4V alloy surfaces. In vitro investigation on agar plate showed inhibition of bacterial growth on most of the laser treated surface. Increased surface roughness and occurrence of magneli phases of titanium dioxide on laser treated surface were probably responsible for the antibacterial behavior exhibited by the laser treated samples. The authors’ results suggested that femtosecond laser surface treatment of Ti6Al4V alloy could find potential application in the development of infection free medical implants for dental and orthopedic usages.