Comparison of Frictional Resistance between Three Self-ligating Brackets and a Conventional Bracket Using Three Different Archwires: An In Vitro Study

Abstract

Aim: To evaluate frictional resistance among three different self-ligating brackets (SLBs) and a conventional bracket with three different archwires. Materials and methods: A total of 120 samples of three different types of mandibular second premolar SLBs—Damon Q, Empower 2, SmartClip brackets, and a Stainless Steel conventional bracket with three types of archwire segments 0.016 inch nickel-titanium (NiTi), 0.019 × 0.025 inch NiTi, 0.019 × 0.025 inch stainless steel were measured. They were divided into four groups, group I = Empower 2 brackets (10), group II = Damon Q brackets (10), group III = SmartClip brackets (10), and group IV = conventional brackets (10) in 0.022 inch slot size with MBT prescription were compared. The three archwires were pulled in each group to determine the frictional resistance using the universal testing machine (UTM) with a 100 gm load cell. Result: One-way analysis of variance (ANOVA) was applied to analyze the group means, and post hoc Duncan’s multiple range test (MRT) was used to compare the mean frictional resistance between the pairs of different bracket groups. The Conventional bracket showed the highest mean values for all three wires, followed by SmartClip, Damon Q, and Empower 2 brackets, in that order. Among the archwires, 0.016 inch NiTi showed the least frictional resistance, while 0.019 × 0.025 inch SS showed the highest values with all three brackets. Conclusion: Among the four brackets, Empower 2 brackets showed the least frictional resistance. The combination of Empower 2 bracket and 0.016 inch NiTi wire showed the least frictional resistance among the different bracket–wire combinations. Hence it can be the preferred bracket for producing smooth, frictionless orthodontic tooth movement. Clinical significance: Friction at the bracket–archwire interface plays a key role in determining the orthodontic tooth movement and thereby influencing the treatment duration. Frictional resistance varies between interactive and passive self-ligating systems. Comparing different SLBs with conventional brackets, as done in this study, allows the best bracket system to be selected based on the tooth movement required.