title: Conventionally ligated versus self-ligating metal brackets--a comparative study.
abstract: The purpose of this study was to compare the frictional properties of four self-ligating metal brackets, Speed, Damon 2, In-Ovation, and Time, with those of three conventionally ligated metal brackets, Time, Victory Twin, and Discovery. The self-ligating Time bracket can also be used as a conventionally ligated bracket. Friction was tested 20 times for each bracket/wire combination using a Zwick testing machine with stainless steel wires in three different wire dimensions (0.017 x 0.025, 0.018 x 0.025, and 0.019 x 0.025 inches). All brackets had a 0.022 inch slot and the prescription of an upper first premolar. The data were statistically analysed with unsigned comparisons of all bracket/wire combinations using the Mann-Whitney U-test and the Games-Howell post hoc test. The results showed almost all brackets to have the lowest frictional force with a wire dimension of 0.018 x 0.025 inch. Friction of the self-ligating brackets using wire with a dimension of 0.018 x 0.025 inches was 45-48 per cent lower than with 0.017 x 0.025 and 0.019 x 0.025 inch wires. Friction of the conventionally ligated brackets showed a 14 per cent or less reduced friction with 0.018 x 0.025 inch wire compared with 0.017 x 0.025 and 0.019 x 0.025 inch wires. The self-ligating metal brackets showed lower frictional forces with a 0.018 x 0.025 inch wire than conventionally ligated brackets, whereas conventionally ligated brackets showed lower friction with 0.017 x 0.025 and 0.019 x 0.025 inch wire. Friction values vary with different bracket/archwire combinations and, therefore, the choice of a bracket system for treatment should consider the correct wire dimension to produce the lowest possible frictional forces.
authors.affiliation: Department of Orthodontics, Regensburg University Medical Center, Germany. claudia.reicheneder@gmx.net
authors.forename: C A
authors.initials: CA
authors.lastname: Reicheneder
authors.forename: T
authors.initials: T
authors.lastname: Gedrange
authors.forename: S
authors.initials: S
authors.lastname: Berrisch
authors.forename: P
authors.initials: P
authors.lastname: Proff
authors.forename: U
authors.initials: U
authors.lastname: Baumert
authors.forename: A
authors.initials: A
authors.lastname: Faltermeier
authors.forename: D
authors.initials: D
authors.lastname: Muessig
mesh_terms: D003799:Dental Stress Analysis; D017276:Friction; D006801:Humans; D008422:Materials Testing; D016382:Orthodontic Appliance Design; D016910:Orthodontic Brackets; D009969:Orthodontic Wires; D014087:Tooth Movement Techniques / Q000295:instrumentation*