title: Measurements of the torque moment in various archwire-bracket-ligation combinations.
abstract: The torque moment generated by third-order bends is important for tooth movement. The purpose of this study was to measure the torque moment that can be delivered by various archwire and bracket combinations at the targeted tooth. Stainless steel (SS) upper brackets with 0.018 and 0.022 inch slots, two sizes of nickel-titanium (Ni-Ti) alloy wires, and three sizes of SS wires for each bracket were used. The wire was ligated with elastics or wire. The torque moment delivered by the various archwire-bracket-ligation combinations was measured using a torque gauge. Statistical analysis was undertaken using analysis of variance (multiple comparison tests and post hoc using Tukey's honestly significant difference test. The torque moment increased as the degree of torque and wire size increased. There was no significant difference in torque moment between the SS and Ni-Ti wires at lower or higher than 40 degrees torque. The torque moment with wire ligation was significantly larger than that with elastic ligation with 0.016 × 0.022 and 0.017 × 0.025 inch Ni-Ti wires in the 0.018 inch slot brackets and the 0.017 × 0.025 and 0.019 × 0.025 inch SS and Ni-Ti wires in the 0.022 inch slot brackets. However, there was no significant difference in torque moment between either ligation method when using the full slot size wires.
authors.affiliation: Department of Orthodontics, Nihon University School of Dentistry, Tokyo, Japan.
authors.forename: Miyuki
authors.initials: M
authors.lastname: Hirai
authors.forename: Akira
authors.initials: A
authors.lastname: Nakajima
authors.forename: Nobuhiko
authors.initials: N
authors.lastname: Kawai
authors.forename: Eiji
authors.initials: E
authors.lastname: Tanaka
authors.forename: Yu
authors.initials: Y
authors.lastname: Igarashi
authors.forename: Masahito
authors.initials: M
authors.lastname: Sakaguchi
authors.forename: Glenn T
authors.initials: GT
authors.lastname: Sameshima
authors.forename: Noriyoshi
authors.initials: N
authors.lastname: Shimizu
mesh_terms: D000704:Analysis of Variance; D003722:Dental Alloys; D003799:Dental Stress Analysis; D020724:Elastomers; D008422:Materials Testing; D009532:Nickel; D016382:Orthodontic Appliance Design; D016910:Orthodontic Brackets; D009969:Orthodontic Wires; D013193:Stainless Steel; D018709:Statistics, Nonparametric; D014025:Titanium; D019415:Torque
chemical_list: D003722:Dental Alloys; D020724:Elastomers; C040654:titanium nickelide; D013193:Stainless Steel; D009532:Nickel; D014025:Titanium