Date of Award
Master of Science (MS)
Introduction: Copper Nickel-Titanium (CuNiTi) is a relatively new composition of Nickel-Titanium (NiTi) archwires that was originally patented in 1991 as part of the Ormco line of wires. The patent has now recently expired and many other orthodontic companies are making their own CuNiTi wires. Advertisement claims have focused on the laboratory benefits of adding Copper (Cu) to the NiTi, however few independent laboratory testings have been conducted on these new wires to verify claims. The purpose of this study was to conduct thermal analysis of CuNiTi for all currently available wires in two Austenite Finish (Af) variants and two commonly used archwire dimensions. Materials and Methods: Ten as-received wires of 27oC and 35oC CuNiTi were tested in 0.018” and 0.016” x 0.022” archwire dimensions. The wires examined were Ormco Copper Nickel Titanium (Ormco, Orange, CA, USA), FLI Copper Nickel Titanium (Rocky Mountain Orthodontics, Denver, CO, USA), Copperloy Nickel Titanium (GAC, York, PA, USA), Copper Nitanium (Henry Schein/Ortho Organizers, Carlsbad, CA, USA), Truflex Copper Nickel Titanium (Ortho Technology, Tampa, FL, USA), and Tanzo Copper Nickel Titanium (American Orthodontics, Sheboygan, WI, USA). Segments of archwire were investigated by differential scanning calorimetry over the temperature range from -100oC to 100oC at 10oC per minute. Results: There were significant differences for all values when comparing across different brands in regards to Heating endset, onset, and enthalpy as well as cooling endset, onset, and enthalpy. Some brands were very close to advertised values, however others were as far away as 4oC from advertised. In addition the difference between higher and lower Af values were as close as 1.5oC for certain brands when expecting 8oC. Conclusions: One cannot expect to have CuNiTi wires perform similarly across different brands even when they are of the same Af and archwire dimension. For certain brands there may be very little difference between higher and lower Af variants.