Effects of reversing the coiling direction on the force-deflection characteristics of nickel-titanium closed-coil springs.

Objective: To investigate the effects of reversing the coiling direction of nickeltitanium closed-coil springs (NiTi-CCSs) on the force-deflection characteristics.

Methods: The samples consisted of two commercially available conventional NiTi-CCS groups and two reverse-wound NiTi-CCS groups (Ormco-Conventional vs. Ormco-Reverse; GAC-Conventional vs.