Surface Roughness Changes on β-Titanium Orthodontic Wires after Corrosion in Various Artificial Saliva Solutions

beta-Titanium orthodontic wires are exposed to three different artificial corrosive environments, modified Fusayama, modified Fusayama with 0.1 % NaF addition, and modified Fusayama with 1.7 % H3PO4 addition, which are similar to the oral cavity conditions. Corrosion behaviours of wires are observed by using weight loss method and scanning electron microscope observations. Afterwards, surface roughness of wires is investigated in details. Consequently, it is determined that corrosion rate of beta-titanium wires exposed to the modified Fusayama solutions with H3PO4 addition is higher because of the acidity of this saliva. Furthermore, maximum increase in surface roughness and skewness are observed in the same environment. Hydrogen embrittlement of titanium is also an important factor for the corrosion of wires.