Evaluation and Comparison of Rate of Canine Retraction Between Titanium Dioxide Nanocoated Stainless Steel Archwire Segments and Uncoated Stainless Steel Archwire Segments: An In Vivo Split Mouth Study

Objectives Our objectives were to compare titanium dioxide (TiO₂) nanocoated stainless steel archwire segments with uncoated stainless steel archwire segments during individual canine retraction. Materials and methods A split-mouth study was carried out in vivo on 15 patients who needed bilateral maxillary canine retraction. One side of each patient's stainless steel archwire was coated with TiO₂ nanoparticles, while the other side was left untreated. Using nickel-titanium closed coil springs and 150 g of force, canine retraction was performed. Digital vernier calipers were used to take measurements at four-week intervals for 16 weeks. Results The rate of canine retraction was statistically significantly higher in the TiO₂ nanocoated archwire segments than in the untreated segments (p < 0.05). At the first, third, and fourth months in particular, significant differences were found (T1: p=0.021*, T3: p=0.021*, and T4: p=0.023*). There were no changes at baseline (T0: p=1.000) or during the second month (T2: p=0.126), suggesting that the beneficial effect of nanocoating became more pronounced as treatment progressed. Overall, the difference in total space closure was modest but statistically significant, with steady advancement of space closure over time. Conclusion TiO₂ nanocoating may enhance the efficiency of orthodontic tooth movement by reducing friction. In the present study, the nanocoated segment showed faster tooth movement compared to the uncoated segment.