According to the Zeiss Company, the microscope was first introduced in otolaryngology in 1950, then to neurosurgery in the 1960ies and to endodontics in the early 1990ies. The introduction of the microscope in dentistry has caused profound effects on the way clinical endodontics is done. Most importantly, the use of scopes provides the ability to find hidden canals. But it is also used in diagnosis to locate microscopic cracks in the tooth. In treatment, microscopes are used to navigate calcified canals, repair perforations, and in retrieval of broken files.