Evaluation of friction of esthetic brackets according to different bracket-wire angulations

Je, Young Ji; Chang, Minn Hii; Lim, Yong Kyu; Lee, Dong Yul

Abstract

OBJECTIVE
The purpose of this study was to evaluate how the friction that occurs during the sliding movement of the archwire through esthetic brackets is differently affected by bracket materials, slot designs, and tip angulations of the archwire.
METHODS
Eight types of brackets with 0.018 inch slots (composite: Brillant (BR); composite with metal slot: Spirit MB (SP); ceramic: Inspire (IN), Signature (SI), Cristaline V (CR); ceramic with metal slot: Clarity (CL), Luxi II (LU); and metal bracket: Integra (IT)), and placed into groups of 20 brackets in each group, were tested in artificial saliva with 0.018 inch stainless steel wire. The wire tip angulations were given as 0, 4 and 8 degrees.
RESULTS
CR group significantly showed the lowest frictional force with all wire tip angulations of 0, 4, and 8 degrees. IN significantly showed the highest frictional force (p < 0.001). BR (polyoxymethylene) had significantly less frictional force than SP (polycarbonate) (p < 0.001) and showed no significant difference between metal brackets. Friction was increased as the wire tip angulations were increased, but no notches were observed on any parts of the archwire.
CONCLUSIONS
According to the results of this study, esthetic brackets are superior or similar to SS brackets from a frictional point of view.