To measure the slot dimensions of 0.022 inch self-ligating upper central incisor brackets from six manufacturers using electron microscopy, to compare the measured dimensions with the manufacturers’ published dimensions, and to determine if the walls of the slots were parallel.
Six self-ligating upper central incisor brackets from four manufacturers (SmartClip and Clarity SL, 3M Unitek, Monrovia, CA, USA; Speed, Strite Industries Ontario, Canada; Damon MX, Ormco, Orange, CA, USA; In-Ovation R and In-Ovation C, Dentsply GAC, Bohemia NY, USA) were imaged with a scanning electron microscope and the slots heights measured. Intra-operator repeatability and accuracy were determined.
All brackets had slot sizes that were significantly larger (
The actual measurements of upper central incisor self-ligating brackets from six manufacturers were larger than the manufacturers’ stated dimension, and the walls of the slots diverged from the bracket bases.