Quantity of apical extruded material and efficiency of five different methods of removing gutta-percha and sealer...

The objective of this study was the comparison, in three clinical situations, of five different methods of removing gutta-percha and sealer from root canals necessitating endodontic retreatment "in vitro". In the first method only hand instruments (files) were used; in the second and third Sonic and Ultrasonic devices were used respectively, and in the fourth and fifth methods Sonic and Ultrasonic devices were used with hand instruments. In order to evaluate these methods, the time required to remove the filling material, the amount of debris remaining in the canals after the deobstruction and the quantity of substances extruded beyond the apex were investigated. The results showed that while the hand method and the combined methods had no statistically significant differences in respect of time spent, the amount of remaining debris was greater in the combined method. On the other hand, the sonic and ultrasonic techniques demonstrated that more time was required for deobstruction when compared to the hand instruments technique, besides a greater quantity of remaining debris in the canal walls. The extruded material beyond the apex was considered non significant in all methods.