Tolerance in a 0.022” x 0.025” bracket slot from three commercial brands used in the Department of Orthodontics of the National Autonomous University of Mexico

Abstract

The aim of this study was to determine the quality in the size of .022” x .025” slots in brackets of three commercial brands (3M Unitek, GAC, ORMCO) used in the Orthodontics Clinic at the Department of Postgraduate Studies and Research at the National University of Mexico. Methods: The sample was divided into three groups of 40 stainless steel upper right premolar brackets from three different commercial brands which were measured in three dimensions: depth, internal height and external height under a Profi le Projector Microscope. Data was statistically analyzed using Student’s t-test and ANOVA in which statistically signifi cant differences (p < 0.05) were obtained between the three commercial brands in all three dimensions. The t-test showed that ORMCO was the closest to standards, GAC and 3M Unitek obtained statistically significant differences, thus separating from standards. All brackets were found to be larger than established.Key words: Slot, tolerance.