Topography and surface chemistry can significantly affect biofilm formation on dental implants. Recently, the γ-TiAl alloy was considered as the most reliable candidates for the preparation of dental implants because of its excellent mechanical strength, chemical stability and biocompatibility. The emphasis of this study lies in the effects of high-speed milling assisted the minimum quantity of lubrication (HSM-MQL), micro-current wire electrical discharge machining (mWEDM), Er,Cr:YSGG laser and sandblasting/largegrit/acid-etching (SLA) treatments on surface morphology, topography, chemical composition, wettability and biofilm-associated infections on the surface of each group. The surface-treated samples were analyzed using a scanning electron microscope (SEM), SEM surface reconstruction, energy dispersive x-ray spectroscopy (EDS) and water contact angle measuring system. SEM and topography images of mWEDM and laser-treated surfaces showed more irregular surfaces compared to SLA and HSM-MQL surfaces. Results showed that mWEDM and laser-treated surfaces revealed hydrophobic behavior. A significant decrease of biofilm formation was observed on mWEDM treated surface due to the hydrophobicity and existence of the copper element in the recast layer chemical composition. Moreover, EDS confirmed that the zirconium, silicon, and fluorine elements were decorated onto the SLA treated γ-TiAl surface that can have a direct effect on the anti-bacterial activity.

Dental implants play an important role in oral health. Titanium dental implants must endure the complex microflora environment of the oral cavity. Moreover, bacterial infections have been considered as one of the most important factors of implant failure. The issue of dental improvement through modification of chemical composition and surface treatment has received considerable critical attention. γ-TiAl as a novo biocompatible material revealed a slower corrosion rate in biological media rather Ti-6Al-4V. The objective of this study is to investigate the effect of Er,Cr:YSGG laser on γ-TiAl in comparison with sandblasted and acid-etched samples as the control groups and machined samples. Wettability, surface roughness, surface topography, scanning electron microscopy–energy dispersive X-ray spectrometer analysis of surface and subsurface of samples were investigated and bacteria counts of two periodontal bacterial strains ( Aggregatibacter actinomycetemcomitans and Eikenella corrodens) were evaluated on the Er,Cr:YSGG laser surface-treated sandblasted and acid-etched and machined samples. The results of this investigation show that Er,Cr:YSGG laser surface treatment affects surface roughness, surface topography, wettability, chemical composition of the surface and bacteria count. Scanning electron microscopy–energy dispersive X-ray spectrometer analysis of the sample revealed the increment of titanium and oxygen content and reduction of aluminum content in the surface and subsurface layer. A. actinomycetemcomitans and E. corrodens count were found from the lowest level to highest in the sandblasted and acid-etched samples, laser samples and machined samples, respectively. Using controlled parameters of Er,Cr:YSGG laser ensured no significant adverse alteration. The findings to emerge from this study revealed the significant correlation between microbial count and wettability. Furthermore, the contact angle strongly correlated with surface roughness.