Evaluation and comparison of the impact of titanium dioxide nanocoating on frictional resistance of orthodontic stainless-steel wires: An experimental study

Objectives The reduction in frictional force during sliding mechanics results in accelerated tooth movement and enhanced anchorage control. Recently, coating archwires with various nanoparticles has been suggested to lower frictional forces. In the present study, the primary objective is to evaluate and compare the efficiency of titanium dioxide (TiO 2 ) nanocoated stainless-steel (SS) wires versus uncoated SS wires in reducing frictional resistance during sliding mechanics, also to assess and compare the surface roughness of TiO 2 nanocoated SS wires and uncoated SS wires. Material and Methods Eighteen straight SS wires of 0.019 × 0.025 inches were divided into, experimental and control groups. The experimental group was coated with TiO 2 nanoparticles and analyzed for surface roughness using an optical profilometer. Frictional resistance and coefficient of friction at 0.5 N and 1 N between the wires and brackets 0.022” slot size were tested using a texture analyzer. Results Uncoated SS wire exhibited significantly higher surface roughness (0.28 ± 0.06 Ra) compared to TiO 2 coated wire (0.037 ± 0.09 Ra). The mean frictional resistance at 0.5 N and 1 N for coated wires were 2.15 ± 0.35 and 2.79 ± 0.30, respectively, while for uncoated wires, they were 1.15 ± 0.22 and 1.64 ± 0.84, indicating higher friction in coated wires. Surface analysis showed the coating peeling off after the friction test. Conclusion Increased frictional resistance between the wire and bracket slot in the experimental group can be contributed due to the peeling off of the coating, to strengthen the evidence on the impact of coated wires on frictional characteristics, more research is required.