Orthodontic treatment with preadjusted appliances and low-friction ligatures: experimental evidence and clinical observations.

Aim: To describe the features of low-friction ligatures during the leveling and aligning phase of fixed appliance therapy with preadjusted brackets.

Methods: Experimental in vitro and in vivo studies were carried out to test the performance of the low-friction system with regard to leveling and aligning of the dental arches, as well as to increasing the transverse dimension of the maxillary arch.

Results: The outcomes of experimental testing showed that the combination of the low-friction ligatures with the superelastic nickel-titanium wires produced a significantly smaller amount of binding at the bracket/archwire/ligature unit when compared to conventional elastomeric ligatures.

Conclusion: The biomechanical consequences of the use of low-friction ligatures were shorter duration of orthodontic treatment during the leveling and aligning phase, concurrent dentoalveolar expansion of the dental arch, and the possibility of using biologically adequate orthodontic forces.