Removal of silver cones and fractured instruments using the Canal Finder System.

Removal of fractured instruments and silver cones was undertaken experimentally and clinically using the automated Canal Finder System. In all cases manual retrieval had been tried and had failed. Fifteen of 50 fragments could be removed completely and 11 fragments could be bypassed using the Canal Finder System. In 24 teeth the use of the Canal Finder was not successful, in 7 teeth the root canal was perforated or the fragment was pushed through the apical foramen. Removal of silver cones was undertaken in 38 root canals with 40 cones. Eighteen of them could be removed using the Canal Finder. Two cones could be bypassed only. Eight of the remaining 20 cones which could not be removed initially, finally could be removed after combined use of the Canal Finder and an ultrasonic device. The results of this study indicate that the Canal Finder System may be used as an auxillary device in difficult cases of removal of silver cones and fractured instruments.