Abstract :
Aim: To compare the frictional resistance between uncoated and nanocoated low-hysteresis superelastic orthodontic archwires using three metal oxides: Aluminium oxide, titanium oxide, and zirconium oxide, when used with metal and ceramic orthodontic brackets.
Materials and Methods: A total of 120 segments of Low-hysteresis superelastic NiTi archwires (Tomy Orthodontics, Japan) measuring 25 mm, were divided into eight groups: uncoated, Al?O?-coated, TiO?-coated, and ZrO?-coated. Each group having 30 segments which were further divided into two subgroups of 15 each; for testing with metal and ceramic brackets. The nanocoatings were applied using a dip-coating method, followed by heat treatment to ensure adhesion. For frictional testing, upper premolar MBT prescription metal and ceramic brackets with 0.022-inch slots (Ormco, Brea, CA, USA) were mounted on a customised jig with a fixed interbracket distance. The archwires were tested individually by threading them through the brackets, and frictional resistance was measured using a universal testing machine at a sliding rate of 2 mm/min under dry conditions for a duration of one minute. Mean frictional values were recorded in N and then paired t test andANOVA with Tukey’s Post hoc LSD tests were done for comparison.
Results: The results showed that the uncoated wire with ceramic bracket showed the highest friction (21.9687 N) and the least friction was found with ZrO? coated wires with metal bracket (3.1253 N). Among the nanocoatings, the ZrO?-coated wires demonstrated the lowest frictional resistance, followed by TiO? and Al?O? coatings. Frictional resistance was significantly higher with ceramic brackets compared to metal brackets across all wire types, but the nanocoatings significantly reduced friction in both bracket types.
Conclusion: Metal oxide nanocoatings on low-hysteresis superelastic archwires significantly reduce frictional resistance, with zirconium oxide providing the most substantial reduction. These findings suggest that nanocoated wires, especially with ZrO?, may enhance the efficiency of orthodontic treatments by minimizing frictional forces.
Keyword :
Friction, Metal brackets, Metal oxide nanoparticles, Superelastic archwires