Measurement of bending deformation for small diameter orthodontic wires.

The stiffness tester and torque meter were found to yield nearly the same measurements of bending deformation for orthodontic wires as small as .007 inch diameter, provided the different bending apparatus are calibrated to each other. Although frictional losses in the test apparatus did not appear to be significant, the test span length does significantly affect measured values of Young's modulus and flexural yield strength, in a manner similar to that previously found for larger-diameter wires.