3M Unitek Hi-T II Stainless Steel Retraction Spring
A stainless steel coil retraction spring available in several arbor diameters, used to retract teeth and close residual space during orthodontic treatment.
The Unitek Hi-T II Stainless Steel Coil Retraction Spring is a coil spring placed on the archwire to retract a tooth or group of teeth, most commonly used during space closure mechanics such as bringing anterior teeth back after extraction sites have been created, or closing residual space left as treatment progresses toward finishing.
Being made from stainless steel rather than a superelastic material like nitinol, this spring behaves with a more traditional force decay pattern, delivering a stronger initial force that tapers as it is activated, which some clinicians prefer for retraction mechanics where a firmer initial pull is wanted.
The spring is available across several arbor diameters, listed in both imperial and metric measurements in the specification data, letting the clinician match the spring to the archwire gauge being used and the specific retraction force desired for a given case. Retraction springs like this are a routine part of space closure mechanics in fixed appliance treatment, cut to the needed length and compressed onto the archwire between the anchor unit and the tooth or teeth being retracted.
Practices doing regular extraction based treatment or general space closure keep a range of arbor diameters in stock to match the archwire sizes they commonly use.
