Relative stiffness of beta titanium archwires.

The number of vendors of beta titanium (TMA type) wires has recently expanded dramatically. Samples of all the available sizes were obtained from most of the major beta titanium vendors. Three new square sizes are now also available. A total of 34 wire samples were tested for stiffness using the new ADA three-point wire-testing jig. Results show that not all beta titanium wires have the same stiffness. The range of variation was from small to large depending on the nominal wire size. There was also a spread of 1.67% to 4.27% in the standard deviation of the average stiffness from vendor to vendor. Burstone's Vari-modulus of elasticity is discussed along with how the properties of beta titanium could be integrated with his concepts. Strategies for using the new sizes of rectangular beta titanium wires for torque are discussed, including their use as working wires and finishing wires. The possibility of replacing stainless steel wires in the final finishing stages is also discussed.