The impact of a dental operating microscope on the identification of mesiolingual canals in maxillary first molars.

The aim of this study was to clinically assess the impact of a dental operating microscope (DOM) on the clinician's ability to locate a second canal in the mesiobuccal root (MB2), also known as the mesiolingual canal. An endodontic specialist treated 180 maxillary first molars using the same protocol for all teeth except for the use of the DOM (n = 90 per group). In the teeth treated without the use of a DOM, a mesiolingual canal was located in 26.