The European Journal of Orthodontics Advance Access published online on February 2, 2009
The European Journal of Orthodontics, doi:10.1093/ejo/cjn104
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Morphological characterization of as-received and in vivo orthodontic stainless steel archwires
* Department of Orthodontics, Katholieke Universiteit Leuven, Belgium
** Department of Metallurgy and Materials Engineering, Katholieke Universiteit Leuven, Belgium
Address for correspondence Dr Guy Willems, Department of Orthodontics, Faculty of Medicine, School of Dentistry, Oral Pathology and Maxillofacial Surgery, Katholieke Universiteit Leuven, Kapucijnenvoer 7, B-3000 Leuven, Belgium E-mail:guy.willems{at}med.kuleuven.be
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Abstract |
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This study was undertaken to evaluate the material degradation of clinical bracket-archwire-contacting surfaces after in vivo orthodontic use. Twenty-four stainless steel multiloop edgewise archwires with two different cross sections (0.016 x 0.016 and 0.016 x 0.022 inches) were used for at least 6 months in the mouths of 14 patients. The surfaces of both as-received (cross-section of 0.016 x 0.016, 0.016 x 0.022, and 0.017 x 0.025 inches) and the in vivo wires were examined using scanning electron microscopy.
The as-received wires exhibited an inhomogeneous surface with different surface irregularities resulting from the manufacturing process. For the in vivo archwires, an increase in the variety, type, and number of surface irregularities were observed. Crevice corrosion occurred not only at surface irregularities formed during manufacturing and orthodontic handling but also at the bracket-archwire-contacting surfaces and at the archwire surfaces coated with plaque and food remnants. This corrosion may be linked to the formation of a micro-environment at these locations. In addition, a limited number of signs of degradation induced during in vivo testing due to wear and friction were observed.