Copper Ni-Ti wires consist of nickel, titanium, copper and chromium. The addition of copper to the alloy enhances the thermal-reactive properties of the wire. Ormco offers four different Copper Ni-Ti series: Damon Copper Ni-Ti and 27°C, 35°C, and 40°C Copper Ni-Ti. The higher the temperature transition (TTR), the lower the relative forces delivered by the wire. The Copper Ni-Ti series provides a wide range of options in selecting and delivering the force of choice and the wire size for the dictates of the case and treatment modality.
Damon Copper Ni-Ti is specifically calibrated for use with the Damon System. Additionally, the surface finish of the wires is smoother to maximize sliding characteristics.
27°C Copper Ni-Ti has a higher relative stiffness than 35°C or 40°C Copper Ni-Ti. As such, clinicians have found it to perform well in round cross-sections or when higher forces or stiffness are desired in rectangular cross-sections.
35°C Copper Ni-Ti, with its TTR close-to-mouth temperature, is soft at room temperature to facilitate engagement. It falls within a very efficient force range when used in the larger round or all rectangular sizes.
40°C Copper Ni-Ti delivers the lowest relative force of all nickel-titanium archwires. For initial alignment, it is best used in the larger rectangular sizes. As such, it may be indicated in very severe cases or in periodontally compromised patients.
Fig. 1—Initial deflection force is lower with Copper Ni-Ti, making it easier to engage severely malposed teeth. As the wire springs back, more-consistent forces are maintained, even in minor deflections.
† Data taken from AJODO 2001; 119: 63-73
Fig. 2—Most so-called heat-activated wires have wide manufacturing tolerances, forcing their transformations to be set near room temperature. Thus they are fully active well before insertion in the mouth. The precision of Copper Ni-Ti allows the wire to be easily engaged before full activation at body temperature, thus true heat activation.
* Data available on request.
** Bioforce is a registered trademark of GAC Corp. Nitinol is a registered trademark of 3M Corp.