Assessment of torque angle of brackets from different brands

Abstract

Aim: To measure torque angle values of brackets designed for canines, comparing it to their prescription values. Methods: One hundred and sixty maxillary (-2 o) and mandibular (-11 o) canine brackets of Roth prescription from the following brands were selected: Abzil, Eurodonto, Morelli and Ormco. The brackets were set in wax and images were obtained by scanning. Reference points were determined over these images, lines drawn and the torque angle was measured. The Student's t-test and the Wilcoxon signed-rank test were used at a significance level of 5%. Results: For maxillary canine brackets, the medium torque angle values were: Abzil-0.93 o (± 0.88 o); Eurodonto 0.13 o (± 0.34 o); Morelli-2.56 o (± 0.50 o), and Ormco-1.16 o (± 1.27 o). For mandibular canine brackets, the values were: Abzil-11.76 o (± 0.40 o); Eurodonto-10.40 o (± 0.25 o); Morelli-11.18 o (± 0.56 o), and Ormco-11.36 o (± 0.30 o). For maxillary canine brackets, the brands Abzil, Morelli, and Ormco presented statistically diferente values from those indicated for prescription. For mandibular canine brackets, the brands Abzil, Eurodonto, and Ormco presented statistically different values from the prescribed ones. Conclusions: Some marketed brands present differences between the torque angle found in the brackets and those recommended in the prescription. However, these differences are clinically acceptable.

Compliance with the ISO 27020:2019 norm of a sample of currently available preadjusted Orthodontic bracket systems. Are the actual dimensions as expected?

“…The torque expression is especially sensitive to the eventual play between the wire and the bracket´s slot. The imprecisions in the manufacturing process inevitably affect the play between the archwire and the slot and, therefore, the torque expression capacity of the appliance [ 6 , 8 , 9 , 26 ]. It is pivotal to know if the appliances provided by the manufacturer respect the nominal declared values.…”

“…The grounding assumption of the straight-wire technique is therefore the correct bracket manufacturing to deliver the required force system and achieve the planned three-dimensional position of the dentition. Quality norms have been established to indicate to the manufactures the required standards [ 6 , 11 ]. The ISO 27020:2019 norm, approved by the European Committee for Normalization, refers to brackets and tubes used in orthodontics and is the reference norm in the European Union.…”

Tip and Torque Accuracy According to the ISO 27020:2019 Norm in Currently Available Pre-Adjusted Orthodontic Brackets

“…The efficiency of torque expression is reduced if play exists between the wire and the bracket slot [12]. The errors introduced during the fabrication process, in terms of slot height and depth, can increase play and reduce the ability of the appliance to effectively express the inbuilt torque information [5,8,11,13]. It is therefore of paramount importance to assess if the brackets available in the market are respecting the nominal declared values.…”

“…The full expression of the information is achieved by inserting an archwire with a cross-sectional size that fully engages the bracket slot. From a theoretical point of view, in a pre-adjusted system, the teeth should be guided to their ideal position without the need for additional wire bending due to the information incorporated in the bracket slot [5,6]. Despite the information incorporated in the bracket slot, in a clinical setting, it is still necessary to bend the archwires to achieve correct alignment and intercuspation at the end of treatment.…”