BMC Oral Health. 2026 May 15. doi: 10.1186/s12903-026-08518-w. Online ahead of print.
ABSTRACT
BACKGROUND: This study aimed to assess the impact of silver and titanium dioxide nano-coatings on stainless steel and nickel titanium arch wires concerning friction, surface roughness and the release of nickel, silver, and titanium ions.
METHODS: A total of 168 arch wires measuring 17.8 cm in length were divided into two groups based on the type of the orthodontic arch wire material: 84 stainless steel (SS) wires and 84 nickel titanium (NiTi) wires. Each group of these wire materials was evenly divided into three subgroups according to the nano coating material: non-coated group (control), titanium dioxide nanoparticles (TiO2NPs) and silver nanoparticles (Ag-NPs). Static friction on a specially designed acrylic plate was measured using a universal testing machine. Surface roughness data was then gathered using a profilometer machine, and inductively coupled plasma-optical emission spectroscopy (ICP-OES) was used to determine the ion release of Ni, Ag and Ti ions. The collected data were compared using a two-way ANOVA and the Bonferroni test for repeated pairwise comparisons. In the ion release test all samples had been incubated in 10 milliliters of artificial saliva and the data was collected at intervals of after 48 h, one week and two weeks, respectively. Then compared using a three-way mixed ANOVA.
RESULTS: The nano-coating effect on arch wires static frictional resistance was statistically significantly higher in the nanocoated wires especially in nanocoated SS arch wires (p < .001). The surface roughness of both arch wires is significantly impacted by the nanocoating as it became lower in nanocoated arch wires especially Ag-NPs coated SS arch wires (p < .001). Ni ion release significantly decreased in SS arch wires coated with TiO2NPs in comparison to SS wires coated with Ag-NPs and to NiTi arch wires coated with Ag-NPs and TiO2NPs (p < .001).
CONCLUSIONS: Ag-NPs and TiO2NPs coatings are suitable for decreasing static friction in arch wires and improving surface roughness. Nano coating can improve surface roughness, static friction resistance especially for SS arch wires. Ion release of Ag and Ti ions in NiTi and SS coated arch wires is in safety concerns associated with nanoparticle dimensions. Ni ion release decreased in nano-coatings so, nano-coatings slightly improved the corrosion resistance especially in SS arch wires coated with TiO2NPs.
PMID:42141410 | DOI:10.1186/s12903-026-08518-w
