Mechanical Testing of Orthodontic Wires

This review article describes the mechanical properties with respect to clinical application of wires used in orthodontics. Mechanical properties of the wires are generally assessed by tensile bending and torsional tests. Although wire characteristics determined by these tests do not necessarily reflect the behaviour of the wires under clinical conditions, they provide a basis for comparison. The characteristics desirable in orthodontic wires are high springback, low stiffness, good formability, high stored energy, biocompatibility and environmental stability, low surface friction and the capability to be welded or soldered auxiliaries. Optimal use of these orthodontic wires can be made by carefully selecting the appropriate wire type and size to meet the demands of a particular clinical situation.