Effectiveness of low binding frictional materials: Evaluation of the binding frictional resistance of improved superelastic nickel-titanium alloy wires with different bracket combinations

Abstract

Introduction: This study aimed to evaluate the binding frictional resistance of improved superelastic nickel- titanium alloy wires (ISW) with different bracket combinations and to verify the effectiveness of low binding frictional materials by applying them in orthodontic treatment. Materials and Methods: Straight stainless steel wire (SSW; 0.016 × 0.022-inch) and straight ISW (0.016 × 0.022- inch) were set to each displaced bracket, and the tensile resistance load was measured. The maximum tensile resistance load was statistically compared using the Tukey test. For exemplification, we treated a typical extraction case of Angle Class I crowding malocclusion with lip protrusion using lower binding frictional materials, which were selected based on tensile test results. Results: The SSW and metal bracket combination had the largest maximum tensile resistance load, and the ISW and metal slot-equipped plastic bracket combination had the smallest load (P < 0.01). In a patient treated using lower binding frictional materials, the active treatment period was 9 months. Satisfactory patient results were obtained without using reinforced anchorage. Conclusions: Binding frictional resistance varies, depending on the archwire and bracket combination. In a multibracket appliance, selecting materials with as low a binding frictional resistance as possible may make a more effective treatment.