Superelastic nickel titanium alloy retraction springs--an experimental investigation of force systems.

The purpose of the present investigation was to study the mechanical characteristics of canine retraction springs made of superelastic nickel titanium (NiTi) alloys. A modified Burstone T-loop was used to construct an experimental canine retraction spring 10 mm in height and 10 mm in length. Twenty-five NiTi T-segments were hand made from the superelastic orthodontic alloys Ormco NiTi and Soar Sentalloy (dimensions 0.