An experimental study on the forces released by ceramic preadjusted brackets with low friction vs. conventional elastomeric ligatures

This in vitro study compared the forces generated by ceramic brackets (Aqua) in presence of low friction ligatures (Slide) and by the same brackets utilized with conventional elastomeric ligatures (CEL) during leveling and aligning phases of orthodontic therapy.

The testing model consisted of five 0.022" preadjusted brackets (second premolar, first premolar, canine, lateral incisor, and central incisor). The canine bracket was welded to a sliding bar that allowed for different vertical positions. The forces generated by means of 0.014" super elastic nickel titanium wire in presence of either low friction bracket/ligature systems or CEL at different amounts of upward canine misalignment (1.5 mm, 3 mm, 4.5 mm, and 6 mm) were recorded.

Significant differences between the low friction systems and CEL were found for all tested variables (p < 0.01) with the exception of the canine misalignment of 1.5 mm. The average amount of released force in the presence of CEL with 3.0 mm of canine misalignment or greater was approximately zero.