2022 Volume 41 Issue 2 Pages 147-155
Recently, orthodontic stainless steel wire (SUS wire) with white coating has attracted attention due to the increasing demand for esthetics, while an alternative method for improving esthetics is required because partial detachment of the coating layer has been clinically reported. Therefore, in this study, we investigated color control of SUS wire by the formation of an oxide layer on its surface using the INCO method.
Color tone of SUS wire could be controlled by this method, and SUS wire with a having color shade close to that of natural teeth was obtained depending on the experimental conditions. The relative amounts of Cr and O in the chemical composition of SUS wire were increased with increasing processing time, so that coloration was caused by optical interference of a chromium-based oxide layer formed after processing. The static friction force against the metal bracket, Vickers hardness, elastic modulus, and maximum strength of SUS wire with a color shade close to that of natural teeth showed no significant difference compared with those of non-treated SUS wire, but corrosion resistance was improved.
