Methods for removing metal obstructions from the root canal

The removal of metallic obstructions is an important part of endodontic retreatment procedures and encounters a number of serious problems. Sometimes removal procedures are extremely easy and can be performed in rather short time, but often it is a very tedious and time-consuming operation with a high number of failures, especially with fractured instruments. Using special devices such as the Masserannkit, the Canal-Finder-System, or ultrasonic systems some fractured instrument cases can be managed successfully. The retreatment of dowel-obturated root canals or failing silver cone cases has a good prognosis and a fairly good success rate. The Masserannkit, post pullers, the Canal-Finder-System and ultrasonic systems have been shown to be helpful devices in removal of root posts and silver cones. Additionally a large number of special devices and techniques for the removal of metal obstructions from the root canal have been described in the literature and will be critically reviewed.