Torque Expression in Stainless Steel Orthodontic Brackets

Abstract

Objective:To evaluate the quantitative effects on torque expression of varying the slot size of stainless steel orthodontic brackets and the dimension of stainless steel wire, and to analyze the limitations of the experimental methods used. Materials and Methods:In vitro studies measuring torque expression in conventional and selfligating stainless steel brackets with a torque-measuring device, with the use of straight stainless steel orthodontic wire without second-order mechanics and without loops, coils, or auxiliary wires, were sought through a systematic review process. Results: Eleven articles were selected. Direct comparison of different studies was limited by differences in the measuring devices used and in the parameters measured. On the basis of the selected studies, in a 0.018 inch stainless steel bracket slot, the engagement angle ranges from 31 degrees with a 0.016 ϫ 0.016 inch stainless steel archwire to 4.6 degrees with a 0.018 ϫ 0.025 inch stainless steel archwire. In a 0.022 inch stainless steel bracket slot, the engagement angle ranges from 18 degrees with a 0.018 ϫ 0.025 inch stainless steel archwire to 6 degrees with a 0.021 ϫ 0.025 inch stainless steel archwire. Active stainless steel self-ligating brackets demonstrate an engagement angle of approximately 7.5 degrees, whereas passive stainless steel self-ligating brackets show an engagement angle of approximately 14 degrees with 0.019 ϫ 0.025 inch stainless steel wire in a 0.022 inch slot. Conclusions:The engagement angle depends on archwire dimension and edge shape, as well as on bracket slot dimension, and is variable and larger than published theoretical values. Clinically effective torque can be achieved in a 0.022 inch bracket slot with archwire torsion of 15 to 31 degrees for active self-ligating brackets and of 23 to 35 degrees for passive self-ligating brackets with a 0.019 ϫ 0.025 inch stainless steel wire. (Angle Orthod. 2010;80:201-210.)

Comparison of Torquing Ability of 0.019” × 0.025” Nickel Titanium and Fiber Composite Archwires -A Cone Beam Computed Tomography Study

“…2016; 11(2):e5967. (28)(29)(30)(31)(32)(33)(34), none of the studies took into account the curved section of the arch as simulation models were done using straight pieces of wire. In the absence of in-vivo studies, extrapolating, the result so obtained, to various clinical settings may not be accurate for any given bracket and archwire combination.…”

Study of the Relationship of Smile Esthetics Between Torque and Dental Arch Width of Posterior Teeth in Orthodontics

“…Observing the results, and coinciding with authors like Archambault et al [7], one could assume that it is difficult to predict the final torque to be obtained at the end of treatment only from a certain system of brackets.…”

“…From a mechanical standpoint, it relates to a structure torque through its longitudinal axis, resulting in the twist angle. Clinically, refers to bucopalatal or buccolingual inclination of the crown or root of a tooth, and is adapted explanation used to describe the rotation along an axial axis [7]. When applied to an interaction between an archwire and a slot of a bracket, it describes the activation generated when twisting an archwire in the slot of a bracket [7].…”

Microimplants in lingual orthodontics

“…20 Üst ve alt kesici dişlerin doğru pozisyona gelmesi ile tedavi sonucunda estetik, fonksiyon ve stabilite sağlanmaktadır.…”