Qualitative Analysis after Instrumentation Using Manual Stainless Steel and Rotary Nickel Titanium Instruments

Objective: To compare qualitatively the instrumentation (areastouched by the endodontic instruments) with manual stainless steeland rotary nickel titanium files.Method: 32 mesiobuccal roots of maxillary molars with a singlecanal and a single apical foramen were examined in vitro. Thecanals were instrumented by the crown-down technique using Ktypefiles and taper .04 Profile files, obtaining a surgical diametercorresponding to a #30 instrument. Next, impression material wasinjected into the root canals. After material setting, the teeth weredecalcified to obtain canal impression. To evaluate the quality ofroot canal instrumentation, the images of the impressions weretransmitted to a 29-inch tv using a video camera coupled to anoperative microscope at ×20 magnification and moderate lightintensity. The examined surfaces were classified as EXCELLENT(smooth surfaces indicating that the walls were touched by theinstrument), GOOD (surfaces with irregularities) and REGULAR(surfaces with irregularities, presence of anatomic complexities,like isthmuses, accessory canals, delta, etc).Results: The analysis of the root thirds and surfaces showed apredominance of the REGULAR classification of instrumentationfor both types of instruments. The worst results were found on thepalatal surface and apical third.Conclusion: There was no statistically significant difference(p>0.05) between the manual stainless steel and rotary nickeltitanium instrumentation techniques when the impressions of theroot thirds and surfaces were analyzed qualitatively