Precision brackets for upper lateral incisors in Bioprogressive therapy

Abstract

Orthodontic brackets, specifically in their slots, are responsible for receiving active orthodontic forces and transferring them to the teeth to be moved. The presence of an altered slot or inaccurate dimensions can influence the mechanical relationship between the bracket and archwire, interfering with the biomechanics of tooth movement. The objective of this study was by comparing the accuracy of slot placement of upper right lateral incisor metal brackets for Bioprogressive Ricketts therapy from five trademarks. The following characteristics were evaluated: height, torque, and internal parallelism of the walls of the slot. The sample included 75 brackets, 15 each from the following trademarks: 3M Abzil, Forestadent, Morelli Rocky Mountain Orthodontics, and Tecnident. Images of the slot profiles were obtained through standardized techniques using scanning electron microscopy, measured by the AutoCAD 2017 software, and compared to Ricketts prescription, respecting standard deviation with the technical and tolerance parameters present in standard ISO 27020. The results indicated that most of the evaluated characteristics were in accordance with the standard parameters, considering the tolerance adopted. There were exceptions found to this pattern of precision in the 3M Abzil brackets with regard to torque variation, and the Morelli brackets in relation to height variation and parallelism between the walls of the slot. Considering the measured dimensional characteristics, the metal brackets used in Bioprogressive Ricketts therapy has satisfactory pattern accuracy; however, there are still some specific inaccuracies in brackets from certain brands that can require more attention during the detailing phase. K E Y W O R D S brackets, parallelism, size, slot, torque

Assessment of orthodontic brackets slot size accuracy in different commercially available brackets: An in vitro study

“…The results of this present study are not in accordance with the studies conducted by Rajashekar K et al (2017) 3 , Araujo AVP et al (2019) 16 , Daga et al (2017) 17 , Park JS et al (2020) 18 and Tepedino et al (2020) 19 . Rajashekar K et al 3 found that 50% of brackets were larger and the remaining 50% were smaller than the stated dimension and all brackets were statistically significant (p≤0.05).…”

Evaluating orthodontic bracket slot dimensions and morphology: A narrative review

“…unit standardization; they are among the researchers who have defined the spectrum of slot and archwire manufacturing features. [ 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 ]…”

“…These comprise leaf gauges, pin gauges, digital gauges, a profile projector microscope, a stereomicroscope, an optical microscope, a scanning electron microscope, and a micro-CT scanner. [ 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 ]…”

Scanning Accuracy of Bracket Features and Slot Base Angle in Different Bracket Materials by Four Intraoral Scanners

“…Regarding the parallelism of the inner wall of the slot, Major et al [24] measured the manufacturing tolerance of the orthodontic bracket slot and reported a convergent taper of 1.47°, a slightly divergent taper below that, and the most rectangle in shape depending on the product. Araujo et al [25] reported that there was no significant difference in torque manufacturing tolerance, and that it converged with respect to the parallelism of the inner wall of the bracket slot, and that the average parallelism was measured from +0.19 to -4.10 depending on the manufacturer [11,26,27]. In this study, the slot base angle was the same as the torque of the bracket prescription, and in order to check the tolerance according to the manufacturer, the torque and parallelism of the actual bracket were measured with a scanning electron microscope, and it was confirmed that it was within the manufacturing error.…”