Torsional properties of Ni-Ti orthodontic archwires

Commercially preformed edgewise Ni-Ti based archwires are used in orthodont ic practice. Two commercially available products were tested in torsion in controlled conditions of moment and temperature, in equipment especially de signed to simulate the environments in clinical use. The results are compar ed with the traditionally used stainless steel archwires. It is shown that by changing the martensitic transformation temperatures through variations of composition, a wide variety in the properties of the archwires can be ob tained according to the necessity of the dentist. (C) 1999 Published by Els evier Science S.A. All rights reserved.