Resistencia friccional de alambres de niquel titanio superelásticos en brackets autoligables activos en movimientos de primer orden: estudio in vitroResistencia friccional de alambres de niquel titanio superelásticos en brackets autoligables activos en movimientos de primer orden: estudio in vitro

Abstract

Objective: The aim of this study is establish the friction force as an indicator of superelastic NiTi round wires (SE) 0.016 and rectangular 0.016 x 0.022" in active self-ligating brakets Empower® Bioquick® in first-rate movements. Materials and methods: Sample of 80 segments NiTi SE preformed arch wire (40 0.016, 40 "0.016x0.022") and two active self-ligating systems (Bioquick® - Forestadent, Empower® - American Orthodontics). Displacement were performed by measuring the force levels 1-1,5-2-2,5 mm, simulating a buccal and lingual movement at a constant speed of 5mm/min in an Instron® universal testing machine. Results: Apropos of load force values was found that the force generated was 0.21 times higher compared Empower® brackets to Bioquick® brackets. As for the type of wire it was found that the rectangular presented 2.92 times more force than round wire. Moreover also observed that the force was -2.44 download times lower than in charge and that this force increased 1 30 times per millimeter of displacement. Conclusions: The Empower® brackets have higher friction compared with brackets Bioquick® with NiTi SE wire 0.016 "and 0.016 x 0.022". The levels of force and stiffness are higher for NiTi wire 0.016 x 0.022 " in loading and unloading regardless of the type bracket used.