Novel methods reveal that parallelism contributes to the functional vertical slot dimension in ceramic and metal brackets.

Objectives:: To validate a novel method for measuring the clinically relevant bracket slot and use these methods to test the hypothesis that various metal injection molded (MIM) and esthetic ceramic injection molded (CIM) brackets have a bracket slot accuracy within 1 mil (0.001") of their reported slot dimension.

Materials And Methods:: A Nikon iNEXIV-VMA-2520 laser microscope was used to measure slots of six series of CIM brackets and two series of MIM brackets via a vision measuring system of 256 gray levels to capture each edge of the slot, largely taking out human subjectivity.