An ideal orthodontic wire should exhibit bio-compatibility, creep resistance, weldability, formability and also, by suitable treatment, a variable elastic modulus or flexural stiffness. New titanium based shape memory effect alloys show promise of being close to this ideal. Based on preliminary studies of Titanium-Molybdenum-Aluminum and Titanium-Vanadium- Aluminum alloys, it has been shown that an elastic modulus range from 2.5 to 9 x 106psi, a 360% variation, can be achieved in these systems. Their assured bio-compatibility, based on the performance of titanium alloys in orthopedics, and their combination of shape memory effect and super-elastic behavior, makes a case for further research to characterize the properties of these two ternary alloys. Being Nickel free any of the adverse tissue reactions observed in people sensitive to this element would be avoided. To commercialize these alloys, further research on the relationship between the properties required for orthodontic application and alloy composition and heat treatment is needed. Processing procedures must also be developed for wire production. These alloys are expected to provide a significant advance in a wide range of orthodontic procedures, and in addition could be valuable new materials for general orthopedics.
