Vacuum Storage of Titanium Treated With UV or NTAPPJ

Objectives: To evaluate the effect of vacuum storage on time-dependent changes in the biological activity of titanium treated with ultraviolet (UV) or nonthermal atmospheric pressure plasma jet (NTAPPJ).
Methods: Grade IV machined-surface titanium discs (diameter, 12.0 mm; thickness, 1.0 mm) were treated with UV (15 min) or NTAPPJ (10 min). Changes in surface characteristics over time during vacuum storage were evaluated using contact angle analysis and X-ray photoelectron spectroscopy immediately after UV or NTAPPJ treatment and at 1, 2, 4, and 8 weeks after the treatment. Changes in biological activity over time were determined by analyzing bovine serum albumin adsorption and early MC3T3-E1 cell adhesion.
Results: Immediately after UV or NTAPPJ treatment, we found no differences between the effects of UV and NTAPPJ treatment on titanium over time. The photocatalytic activity due to UV and increased reactive oxygen species (ROS) production and tentative ROS/UV synergistic activity due to NTAPPJ treatment caused a significant increase in the hydrophilicity of the surface and a decrease in the atomic percentage of carbon, which consequently increased protein adsorption and cell adhesion compared to the findings for the control, which was not subjected to any treatment. During vacuum storage over a period of 8 weeks, in both groups, atomic percentage of carbon, hydrophilicity of the surface, protein adsorption, and cell adhesion did not differ from their corresponding values obtained immediately after treatment.
Conclusions: The results show that enhanced hydrophilic surface characteristics and biological activity of titanium due to UV or NTAPPJ treatment can be maintained with vacuum storage for up to 8 weeks after treatment. In the actual clinical setting, if a suitable vacuum storage method is used, titanium implants pretreated with UV or NTAPPJ can be sold without necessarily having to perform surface treatments immediately before the placement of the implants.