A clinical trial of alignment of teeth using a 0.019 inch thermal nitinol wire with a transition temperature range...

Nitinol has a unique property which is of practical use to the orthodontist. That property is its extreme elasticity when it is drawn into high-strength wire. Nitinol wire is much more difficult to deform during handling and seating in bracket slots than stainless steel wire. At the time of this writing, it is nitinol's extreme elasticity that offers the clinician an advancement in the application of orthodontic materials. This characteristic reduces the loops formerly needed to level a dentition. The wire can be used for longer periods of time without changing it, and it can shorten treatment time needed in leveling the dentition. Nitinol has another remarkable characteristic, that of being able to return to a previously manufactured shape when it is heated through a transition temperature range (TTR). If we are to take advantage of this property, the wire must first be set into the desired shape while undergoing a high-temperature heat treatment. After the wire has cooled to room temperature, it may be deformed within certain strain limits. When heated to its unique TTR, it will "remember" its shape and return to the original configuration. It is this type of wire that is being reported on in the case report that follows.