An in vitro comparative evaluation of surface roughness characteristics of different orthodontic archwires: An atomic force microscopy study

Background. The present study evaluated and compared the surface roughness (SR) of five different types of orthodontic archwires made by two different manufacturers.

Methods. In this in vitro study, 10 samples of five different archwires comprising of three types of shape memory wires, SmartArch (Ormco), Damon (Ormco), Heat-activated NiTi (HANT) (G&H Orthodontics), Stainless Steel wire (SS) (Ormco), and conventional NiTi (G&H Orthodontics) were examined by atomic force microscopy (AFM). The processing of 3D images was carried out using Gwyddion software, from which the root mean square (rms), the roughness average (Ra), and the maximum height (mh) of the scanned surface profile were documented. The data were analyzed with one-way ANOVA followed by post hoc Tukey tests for intergroup comparisons.

Results. The mean SR of SS wires was the least (Ra=8.70±0.17), followed by NiTi wires (10.29±2.00) with a significant difference between them (P<0.05). Among the three shape-memory wires, the HANT wires had the least SR (Ra=22.97±16.56) compared to SmartArch wires (Ra=25.55±3.78) and Damon wires (Ra=25.67±4.54), but the difference was not significant (P>0.05).

Conclusion. The SS wires by Ormco had the least SR followed by G&H orthodontics NiTi wires. The three different shape-memory wires tested had no significant difference in SR values.