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Corrosion resistance of stressed NiTi and stainless steel orthodontic wires in acid artificial saliva
Author(s) -
Huang HerHsiung
Publication year - 2003
Publication title -
journal of biomedical materials research part a
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.849
H-Index - 150
eISSN - 1552-4965
pISSN - 1549-3296
DOI - 10.1002/jbm.a.10463
Subject(s) - materials science , corrosion , nickel titanium , scanning electron microscope , metallurgy , x ray photoelectron spectroscopy , auger electron spectroscopy , pitting corrosion , composite material , shape memory alloy , chemical engineering , physics , nuclear physics , engineering
Abstract The purpose of this study was to investigate the corrosion resistance of stressed NiTi and stainless steel orthodontic wires using cyclic potentiodynamic and potentiostatic tests in acid artificial saliva at 37°C. An atomic force microscope was used to measure the 3‐D surface topography of as‐received wires. Scanning electron microscope observations were carried out before and after the cyclic potentiodynamic tests. The surface chemical analysis was characterized using X‐ray photoelectron spectroscopy and Auger electron spectroscopy after the potentiostatic tests. The cyclic potentiodynamic test results showed that the pH had a significant influence on the corrosion parameters of the stressed NiTi and stainless steel wires ( p < 0.05). The pitting potential, protection potential, and passive range of stressed NiTi and stainless steel wires decreased on decreasing pH, whereas the passive current density increased on decreasing pH. The load had no significant influence on the above corrosion parameters ( p > 0.05). For all pH and load conditions, stainless steel wire showed higher pitting potential and wider passive range than NiTi wire ( p < 0.001), whereas NiTi wire had lower passive current density than stainless steel wire ( p < 0.001). The corrosion resistance of the stressed NiTi and stainless steel wires was related to the surface characterizations, including surface defect and passive film. © 2003 Wiley Periodicals, Inc. J Biomed Mater Res 66A: 829–839, 2003