Evaluation of friction in self-ligating brackets subjected to sliding mechanics: An in vitro study

Abstract

Introduction: Friction generated at the bracket/archwire interface during sliding mechanics can reduce the efficiency of orthodontic movement. The ligation method employed to tie the archwire to the bracket plays an important role in determining this friction. Methods: This study compared the frictional force generated by four different types of selfligating brackets (Time ®, Damon 2 ®, In-Ovation R ® and Smart Clip ®) with a group of conventional orthodontic brackets (Dynalock ®) that require the use of traditional elastomeric ligatures (ExDispens-A-Stix ®), which served as the control group. Static friction force was measured using an EMIC DL ® 500 universal testing machine using stainless steel round 0.018-in and rectangular 0.017x0.025-in archwires. Results: ANOVA and Tukey's test showed low levels of friction in the four self-ligating brackets in tests with the 0.018-in wire (P <0.05). However, the results noted when the self-ligating brackets were tested using 0.017×0.025-in archwires showed high resistance to sliding in the self-ligating groups.