Plasma coloring of Ti via air atmospheric pressure plasma jet for dentistry

The aesthetic appeal of titanium dental implants is compromised by unattractive coloration, and extended exposure to bodily fluids can result in the release of ions, potentially causing infection or inflammation. This study introduces a direct method for oxidizing titanium through plasma coloring to enhance biocompatibility. Utilizing a tornado-type atmospheric pressure plasma jet (APPJ) with compressed dry air as the working gas, sub-stoichiometric titanium oxide was produced on sample surfaces. Analysis of reactive oxygen species (ROS) in air plasma via optical emission spectroscopy offers valuable insights into the interaction between plasma and the surface during the oxidation process. Quantification of surface coloration in titanium samples before and after treatment with air-APPJ was conducted using CIE chromaticity diagrams and color temperature analysis. This analytical approach enabled the assessment of thermal and plasma-chemical impacts of plasma coloring on the development of the sub-stoichiometric titanium oxide layer. The resulting oxide layers from the APPJ process exhibited a vibrant golden shade, along with enhanced surface hydrophilicity, improved anticorrosion properties, and enhanced cellular responses.