Evaluation of friction in metal, ceramic and self-ligating brackets submitted to sliding mechanics

Abstract

Objective With the purpose of evaluating the best results for a proposed orthodontic treatment, the aim of this research was to verify the frictional force between archwires and orthodontic brackets in sliding mechanics. Material and method Three different types of brackets were used: conventional metal, self-ligating metal and conventional polycrystalline esthetic type (n=10), totaling 30 brackets and .019 x .025 inches stainless steel rectangular wire. An acrylic plate was used. The wire was fixed to the brackets (conventional metal and conventional polycrystalline esthetic) with esthetic elastomeric ligation. The acrylic plate together with the 019 x 0.025 inches wire fitted to it was attached to the base plate of the Instron 4411 universal test machine so that it was positioned perpendicular to the ground. The bracket was drawn through the archwire segment at a speed of 5 mm / minute for a distance of 5 mm. For each type of bracket, ten tests were performed, with the bracket and archwire set being changed for each repetition. Data were analyzed by one-way Analysis of Variance (p <0.0001) and the Tukey Test (p <0.05). Result Convencional metal and self-ligating brackets presented similar friction (p>0.05), while ceramic bracket presented higher frictional resistance during sliding test (p<0.05). Conclusion It was concluded that the type of bracket influenced the frictional force value obtained, and better results were found when the metal and self-ligating brackets were used. The ceramic bracket presented a higher frictional force value.

Assessment of Rate of Orthodontic Tooth Movement with Different Modalities of Ligations

“…It is assumed that the use of self-ligating brackets considerably reduce friction and therefore the burden on anchorage. Self-ligating brackets have a lower degree of frictional resistance during sliding mechanics, according to studies comparing them to different ligating systems for conventional brackets (8,9) . However a large number of systematic reviews have studied the evidence for the efficacy of selfligating brackets and conventional brackets, and the conclusions reached are not conclusive to support the superiority of one method over the other (10,11) .…”