The Relation between Type of Ligature and Force Delivered by Orthodontic Arch Wire

AIMS: This in vitro study aims to compare the deactivation force, delivered as a result of releasing superelastic arch wire from 4 mm to 2.5 mm in horizontal direction at the area of right maxillary canine on standard model of teeth, by using three different methods to ligate the wire to the brackets. MATERIALES AND METHODS: Materials of this study include three sets of Synergy brackets 0.022P Px 0.028 inch, molar buccal tubes, thirty arch wire , 0.016 inch round preformed arch superelastic nickel-titanium wires, were divided to three groups according to ligation method, the first group was ligated with preformed steel wire ligatures ,the second group with elastic ligatures as o configuration and in third group with elastic ligature as c configuration. The measurements were completed at room temperature of 27±5 in dry media by machine designed by college of mechanics engineering /Mosul university and the results were compared among the three methods of ligation. RESULTS: Significant difference in deactivation forces (p < 0.05) were observed. C configuration elastic ligatures had the higher mean of deactivation force (332 gm) than either o configuration or steel wire ligatures (268.5 gm), (267.9 gm) respectively. CONCLUSIONS: Decreasing the ligation force by using C configuration elastic ligatures to ligate the wire to Synergy bracket is potentially adequate to use at the beginning of leveling and aligning stage of orthodontics that allow the arch wire to generate its force without more missing due to high friction, as occurred by the use of stainless steel wire ligatures or o configuration elastic ligatures.