Comparison of friction coefficient and surface roughness on stainless steel nickel titanium, and nickel-titanium copper wires to standard edgewise brackets: An experimental in vitro study

Aim: The aim of this study was to investigate the friction and the difference in the roughness of the wire on the standard edgewise bracket. Materials and Methods: This was an experimental laboratory study with a posttest only control group design. The number of samples in this research was 21. The samples were divided into three groups (n = 7) consisting of 0.016 ' ' x 0.022 ' ' stainless steel archwire (SS group), 0.016 ' ' x 0.022 ' ' nickel-titanium archwire (NiTi group), and 0.016 ' ' x 0.022 ' ' nickel-titanium copper archwire (NiTiCu group). The bracket used in each group is standard edgewise slot 0.018. Friction coefficient test was conducted by creating an examination tool from acrylic to fixate the bracket with a size of 2cm x 5cm. The bracket was then attached using glue (polyvinyl acetate) and the archwire was fixated to the bracket using power O. After the friction test, three samples were taken from each group to be tested morphology and topography of each type using scanning electron microscope (SEM). Statistical analysis used in this research is using one-way analysis of variance (ANOVA) to find out the comparison of variables and Tukey's honest significant difference (HSD) to find out the comparison between three groups (P < 0.05). Results: The lowest friction coefficient was found in SS archwire, which consecutively followed by NiTiCu and NiTi. The smoothest archwire surface observed by SEM was SS, followed by NiTiCu and NiTi. Conclusion: SS wire has the smoothest archwire surface and the lowest frictional force, so it is well used for the teeth movement in space closing on edgewise bracket.