The Cytotoxic Effect of Titanium Oxide Surface Modified Orthodontic Stainless Steel Wires
Background: The fixed orthodontic mechano therapy has been associated with white spot lesions and plaque accumulation. Titanium oxide (TiO2) is a compound that possesses clinically significant anti-microbial action especially against lactobacillus and streptococci. However the safety of the TiO2 coated wires has still not been tested. In this study, we evaluated the cytotoxic effects of TiO2 coated stainless steel orthodontic wires. To assess the same, we used A549 cells as experimental cell line. Cells were categorized into 4 groups (n=6/group): cellular control group, represented by the cell growth; negative control group (stainless steel wire) positive control group (hydrogen peroxide), experimental group (titanium oxide coated stainless steel wires). The cultures were carried out either on 6 well plates or 96 well plates and pictures were captured using a microscope or assessed by MTT assay.
Results: MTT assay revealed no cytotoxic effect by TiO2 coated wires as compared to control. Similarly, structural assessment of cellular morphology and nuclear membrane structure further showed no change in toxic effects of TiO2 coated SS wires on the cells.
Conclusion: Despite the limitations of this study, we demonstrated that titanium oxide coated wires had no cytotoxic effects like uncoated stainless steel wires and that there is a strong demand for long-term studies of TiO2 coated wires and brackets, with a strong focus on the cytotoxic properties, concentrations and exposure times, to make the desired applications for TiO2 coated wires safe and suitable for orthodontic use.