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Updated: May 31, 2026
Force System with Vertical V-Bends: A 3D In Vitro Assessment of Elastic and Rigid Rectangular Archwires
Published on: July 24, 2018
Comparisons of nanoindentation, 3-point bending, and tension tests for orthodontic wires
Masahiro Iijima1, Takeshi Muguruma, William A Brantley
1Division of Orthodontics and Dentofacial Orthopedics, Department of Oral Growth and Development, School of Dentistry, Health Sciences University of Hokkaido, Ishikari-Tobetsu, Japan. iijima@hoku-iryo-u.ac.jp
Introduction:
The purposes of this study were to obtain information about mechanical properties with the nanoindentation test for representative wire alloys and compare the results with conventional mechanical tests.
Methods:
Archwires having 0.016 × 0.022-in cross sections were obtained of 1 stainless steel, 1 cobalt-chromium-nickel, 1 beta-titanium alloy, and 2 nickel-titanium products. Specimens of as-received wires were subjected to nanoindentation testing along the external surfaces and over polished cross sections to obtain values of hardness and elastic modulus. Other specimens of as-received wires were subjected to Vickers hardness, 3-point bending, and tension tests. All testing was performed at 25°C.
Results:
Differences were found in hardness and elastic modulus obtained with the nanoindentation test at the external and cross-sectioned surfaces and with the conventional mechanical-property tests. Mechanical properties obtained with the nanoindentation test generally varied with indentation depth.
Conclusions:
The 3 testing methods did not yield identical values of hardness and elastic modulus, although the order among the 5 wire products was the same. Variations in results for the nanoindentation and conventional mechanical property tests can be attributed to the different material volumes sampled, different work-hardening levels, and an oxide layer on the wire surface.
