Influence of ligation method on friction resistance of lingual brackets with different second-order angulations: an in vitro study.

Graziane Olímpio Pereira,Marcos Gabriel Do Lago Prieto,Lucas Prieto,Carla Maria Melleiro Gimenez,Roberta Tarkany Basting

doi:10.1590/2177-6709.21.4.034-040.oar

Graziane Olímpio Pereira, Marcos Gabriel Do Lago Prieto + Show 3 more

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https://doi.org/10.1590/2177-6709.21.4.034-040.oar

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Abstract

ABSTRACTObjective: To evaluate stainless steel archwire static friction in active and passive self-ligating lingual and conventional brackets with second-order angulations. Methods: Two conventional lingual brackets for canines (STb light/Ormco; PSWb/Tecnident), and two self-ligating brackets, one active (In-Ovation L/GAC) and the other passive (3D/ Forestadent), were evaluated. A stainless steel archwire was used at 0°, 3° and 5° angulations. Metal ligatures, conventional elastic ligatures, and low friction elastic ligatures were also tested. A universal testing machine applied friction between brackets and wires, simulating sliding mechanics, to produce 2-mm sliding at 3 mm/minute speed. Results: Two-way analysis of variance demonstrated a significant effect of the interaction between brackets and angulations (p < 0.001). Tukey test indicated that the highest frictional resistance values were observed at 5° angulation for In-Ovation L, PSWb bracket with non conventional ligature, and STb bracket with metal ligature. As for 3D, PSWb with conventional or metal ligatures, and STb brackets with non conventional ligature, showed significantly lower static frictional resistance with 0° angulation. At 0° angulation, STb brackets with metal ties, In-Ovation L brackets and 3D brackets had the lowest frictional resistance. Conclusions: As the angulation increased from 0° to 3°, static friction resistance increased. When angulation increased from 3° to 5°, static friction resistance increased or remained the same. Self-ligating 3D and In-Ovation L brackets, as well as conventional STb brackets, seem to be the best option when sliding mechanics is used to perform lingual orthodontic treatment.

Highlights

Lingual brackets are different from labial brackets in regard to configuration and clinical aspects
Tukey test showed that there was no significant difference in static friction generated by the evaluated brackets-ligatures for the test condition without angulation (0°)
In regard to all angulations (Table 2), conventional STb bracket with conventional ligature presented significantly lower statistical friction than all the other groups represented by bracket-ligatures, with the exception of groups in which STb and bracket metal ligature were used

Summary

Introduction

Lingual brackets are different from labial brackets in regard to configuration and clinical aspects. Some factors influencing friction resistance are related to the material composing brackets and wires, surface conditions of arches and bracket slot, archwire cross-section, torque at the wire-bracket interface, bonding strength, use of self-ligating brackets, interbracket distance, presence of saliva and influence of oral functions.[3] In vitro studies have evaluated friction resistance among different alloys and wire calibers by means of several ligation methods and material of buccal orthodontic brackets with alterations in angulation, using models with one, three, five and ten brackets, and typodonts to simulate different situations.[4,5,6,7,8,9,10] few studies on friction produced by lingual brackets have been published.[2,11,12]

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