Forces produced by different non-conventional brackets or ligature systems during orthodontic alignment

AIM: To analyze the forces of four types of passive stainless steel self-ligating brackets (SLBs; Carriere, Damon3, SmartClip, Opal), and of two non-conventional elastomeric ligature-bracket (Slide, Synergy) low-friction systems when compared with conventional elastomeric ligatures on stainless steel brackets during the alignment of apically or buccally displaced teeth. MATERIALS AND METHOD: A model consisting of five brackets (from second premolar through to the central incisor) was used to assess the forces released by the seven different bracket-ligature systems with 0.012 inch superelastic nickel titanium wire in the presence of different amounts of apical or buccal canine displacement (1.5, 3.0, 4.5 and 6.0 mm). The comparisons between the different types of bracket/wire/ligature systems were performed with three-way ANOVA and Tukey’s post-hoc tests (P < .05). RESULTS: For apical or buccal canine misalignments of 1.5 and 3.0 mm both low-friction and conventional systems released an adequate amount of force for bracket alignment. In the presence of larger amounts of apical or buccal canine displacement (4.5 or 6.0 mm) the low-friction systems produced a significant amount of force, while this amount dropped to zero for the conventional system. CONCLUSIONS: Conventional ligature-bracket systems produced levels of force similar to those generated by low-friction systems in the presence of 1.5 or 3.0 mm of apical or buccal tooth displacements. No significant differences were found between SLBs and non-conventional elastomeric ligature-bracket low-friction systems.