Endodontists have frequently boasted that they can do much of their work blindfolded simply because there is “nothing to see.” The truth is that there is a great deal to see with the right tools.

In the last 15 years, for nonsurgical and surgical endodontics, there has been an explosion in the development of new technologies, instruments, and materials. These developments have improved the precision with which endodontics is performed. These advances have enabled clinicians to complete procedures that were once considered impossible or that could be performed only by talented or lucky clinicians. The most important revolution has been the introduction and widespread adoption of the operating microscope (OM).

OMs have been used for decades in other medical disciplines: ophthalmology, neurosurgery, reconstructive surgery, otorhinolaryngology, and vascular surgery. Its introduction into dentistry in the last 15 years, particularly in endodontics, has revolutionized how endodontics is practiced worldwide.

Until recently, endodontic therapy was performed using tactile sensitivity, and the only way to see inside the root canal system was to take a radiograph. Performing endodontic therapy entailed “working blind,” that is, most of the effort was taken using only tactile skills with minimum visual information available. Before the OM, the presence of a problem (a ledge, a perforation, a blockage, a broken instrument) was only “felt,” and the clinical management of the problem was never predictable and depended on happenstance. Most endodontic procedures occurred in a visual void, which placed a premium on the doctor’s tactile dexterity, mental imaging, and perseverance.

The OM has changed both nonsurgical and surgical endodontics. In nonsurgical endodontics, every challenge existing in the straight portion of the root canal system, even if located in the most apical part, can be easily seen and competently managed under the OM. In surgical endodontics, it is possible to carefully examine the apical segment of the root end and perform an apical resection of the root without an exaggerated bevel, thereby making class I cavity preparations along the longitudinal axis of the root easy to perform.