Frontiers in Dentistry (Feb 2016)
Effect of Topical Fluoride on Surface of Cast Titanium and Nickel-Chromium: An In Vitro Study
Abstract
Objectives: The aim of this in-vitro study was to evaluate the effect of topical fluoride on surface of cast titanium and nickel-chromium. Materials and Methods: Thirty-nine rectangular specimens of titanium (grade 2) and 39 rectangular specimens of nickel-chromium were cast in equal dimensions and divided into three groups of 13 samples each. Group one specimens of titanium and nickel-chromium were placed in 2% neutral sodium fluoride (NaF) solution for 16 minutes. Group two specimens of titanium and nickel-chromium were immersed in 1.23% acidulated phosphate fluoride (APF) gel for eight minutes. Group three specimens of titanium and nickel-chromium were immersed in distilled water for 16 minutes. The surface roughness of the specimens was evaluated and the data were analyzed using two-way ANOVA and post-hoc comparison test with the level of significance set at 5% (P0.05). Qualitative SEM and EDS analyses further revealed the surface corrosion of titanium (group two) and localized mild corrosive pitting of nickel-chromium specimens (group two). Conclusion: Topical fluoride with acidic pH affects the surface roughness of titanium and to a certain extent, nickel-chromium. Neutral NaF solutions cause no significant change in corrosion resistance of titanium or nickel-chromium.
