| The only two choices for esthetic orthodontic brackets today are ceramics or composites, both having functional and mechanical limitations. Most orthodontic brackets are unaesthetic and manufactured from stainless steel, containing nickel as a component, which is a potential allergen. This leads to a problem of orthodontic bracket selection. Consequently, it is very important to explore the use of other materials for manufacturing orthodontic brackets. The purpose of this study was to explore the process of anodizing titanium orthodontic brackets for the purpose of color addition including shades of white. Sheet titanium was cut into 12mm x 12mm squares, pressed at 1000psi to ensure flatness, then etched in a solution of ammonium persulfate and sodium fluoride for 10min at 80°C, then rinsed. Electrolytic oxidation was then completed utilizing 10% H2SO4 as the electrolyte. Voltage was increased in 2-volt increments from 6 to 94 volts (n = 44). Once oxidized, color evaluation was completed with a small area (8mm diameter measuring area) colorimeter (Minolta CR-220b). The L*a*b* values were determined for each sample and the CIELAB color difference was determined between samples (ΔE), which is the algebraic distance between two points in the color space. The only measured variables were ΔVolts, ΔL*, Δa*, Δb*, and ΔE. From these values, a correlation between voltage and color produced was plotted. Results showed that altering the surface appearance of titanium orthodontic brackets through an anodization process is possible and can render brackets with colors throughout the color spectrum; however, shades of white were not achieved. |
