It is reported that the operating microscope was originally used in ophthalmology, plastic surgery and other disciplines with high precision requirements, and began to be used in the treatment of endodontic diseases in the 1990s. Because the operating microscope can provide more sufficient light and good magnification effect, it has changed the status quo of clinicians' diagnosis and treatment based on feelings and experience for a long time, and gradually applied to many fields of endodontic treatment.

At present, micro-root canal therapy is an important means of root canal retreatment. Operating under the operating microscope can make clinicians change the guessing operation into direct vision operation, make clear the operator's operation direction, and play an irreplaceable role in root canal positioning and dredging, thus significantly improving the success rate of root canal retreatment for patients who failed the initial treatment.