Effect of Interbracket Distance on Load-Deflection Property and Resistance to Sliding in Orthodontic Appliances

Abstract

Introduction: Interbracket distance (IBD) plays a key role in load deflection and frictional resistance in the biomechanics of tooth movement. Aim: The aim of this study was to assess the influence of load deflection and friction between the bracket and archwire for a specific load on different bracket designs. Materials and Methods: IBD brackets ( n = 60), Sondhi Mini Uni-Twin brackets ( n = 60), low profile brackets ( n = 60), and Victory conventional brackets ( n = 60) were selected for the study. Load deflection was measured using a universal testing machine on 0.016″ nickel-titanium (NiTi) wire. A universal testing machine was used to measure the frictional resistance on 0.019″ × 0.025″ stainless steel wire. Results: The load deflection of 0.016″ NiTi wire was the highest in IBD followed by Sondhi Mini Uni-Twin, Sondhi conventional, and Victory conventional. Static friction and kinetic friction were the highest in Victory conventional brackets followed by low profile brackets, Sondhi Mini Uni-Twin, and IBD brackets. Conclusions: Load-deflection property will increase with increase in IBD, and frictional resistance will decrease with increase in IBD.