3M™ Unitek™ Nitinol Heat-Activated Archwire is a thermally activated, super-elastic nickel-titanium archwire — the easiest of the Nitinol family to engage, delivering light continuous forces that move teeth efficiently in the early phases of treatment. Body heat activates the wire after insertion, allowing it to recover its programmed arch form gradually rather than placing high initial loads on the dentition. 3M Unitek pioneered the use of nickel-titanium in orthodontic wire progression more than two decades ago, and Nitinol Heat-Activated has remained a leveling-and-aligning workhorse alongside Nitinol Classic and Nitinol Super-Elastic in the same family. Available in round and rectangular cross-sections and across the full OrthoForm™ I Tapered, II Square and III Ovoid arch forms for both upper and lower arches.