Efficiency of Using Microscope with Ultrasonics in Nonsurgical Endodontic Retreatment

The aim of the study was to study the effectiveness of using cli- nical microscope and ultrasonics with rotary Universal Protaper files in removing gutta-percha and sealer from root canals. Twenty single straight-rooted, extracted human mandibular premolars were prepared, filled with gutta-percha and sealer (Zinc oxide with eugenol). Specimens were then divided into two groups. Root filling material was removed using rotary Universal Protaper system with eucalyptol in group 1 (n=10); Rotary Universal Protaper system with eucalyptol followed by using microscope with ultrasonic tip were applied in the group 2 (n=10). After retreatment, the efficacy of each technique was exami- ned at 8× magnification of a stereomicroscope then the images were analyzed using AutoCAD 2010 according to Hulsmann and Stotz scale. Data were statistically analyzed using Mann–Whitney U-test. There was a significant difference when using clinical micros- cope and ultrasonics (p