In vitro study to compare the accuracy of four diagnostic methods for locating the second mesiobuccal canal in maxillary molars

Abstract

The aim of this in vitro study is to compare the efficacy of three diagnostic methods, Direct visual method, Magnifying loupes and Dental operating microscope in recognising all the canals of the root canal system in maxillary first molars using CBCT and reference standard method. A total of 65 maxillary first molars were selected for this study. Teeth selected were evaluated by Periapical radiographs and CBCT. Access cavities of selected extracted human maxillary first molars were prepared, and the floor of the pulp chamber was then explored to locate the MB2 canal in five stages: Stage I (Direct Visual Method), Stage II (under ×3.5 Magnifying Loupes with light-emitting diode [LED] light), Stage III (Under Dental Operating Microscope), and Stage IV (Cross-sectioning was done below CEJ and the sections were evaluated using stereomicroscope at 10x magnification). The descriptive statistics were tabulated using Chi square test to compare the efficacy between the diagnostic methods. Senstivity, specificity, Positive /Negative predictive values were calculated for each method. The results obtained in this study showed that CBCT was most accurate with the dimensional accuracy of 96% followed by Dental operating microscope which performed better (with the diagnostic accuracy of 76%) than the magnifying loupes (with the diagnostic accuracy of 64%) direct visual method (with the diagnostic accuracy 60%). The dental operating microscope was most effective in the detection of MB2 canals followed by magnifying loupes and direct visual method. Additionally, CBCT could be used as a supplementary diagnostic tool in cases in which canals are not found using the methods available in the dental office.