Evaluation of antibacterial activity and biocompatibility of nano-titanium dioxide coatings prepared by atomic layer deposition for dental titanium abutments

To reduce the adhered bacteria on the dental titanium (Ti) abutments and the risk of peri-implantitis, an antibacterial nanometer titanium dioxide (nano-TiO2) coating was developed by atomic layer deposition (ALD). The effects of the nano-TiO2 coatings on surface characteristics, antibacterial efficacy, biocompatibility, and corrosion resistance of Ti abutment materials were investigated. Specifically, the colors of Ti samples were changed from silver-gray to blue, yellow, and purple corresponding to the coating thicknesses were 50 nm, 100 nm, and 150 nm, respectively. Moreover, these coatings with different thicknesses all presented uniform morphologies with anatase TiO2 phases and hydrophobic characteristics. Simultaneously, the prepared coatings exhibited strong antibacterial effects against Staphylococcus aureus (S. aureus), Streptococcus mutans (S. mutans), and Porphyromonas gingivalis (P. gingivalis), which were independent of coating thicknesses. Additionally, Ti substrates coated with 100 nm nano-TiO2 demonstrated exceptional cell compatibility and corrosion resistance. In conclusion, these antibacterial and biocompatible nano-TiO2 coatings prepared by ALD possess great potential in dental aesthetic restorative materials.