الفهرس | Only 14 pages are availabe for public view |
Abstract The purpose of this study was to compare the shaping ability of two rotary endodontic systems: NRT and ProTaper Universal. Sixty extracted permanent human mandibular molars with mesiobuccal canal curvature between 20{u00B0} and 40{u00B0}, according to Schneider{u2019}s method. The mandibular molars were: equally divided into two groups; thirty mesiobuccal canals for each (n=30), according to the rotary instrument used to prepare the root canal either NRT or ProTaper. The parameters evaluated were: the extent and direction of canal transportation, centering ratio, post-instrumentation cross-sectional canal circularity and minimum remaining dentin thickness at two levels: 2mm from the apex (apical level) and height of maximum root curvature (coronal level). The parameters were evaluated using the modified Bramante technique where the mesial roots were resected and embedded in transparent resin blocks using custom made mold, the roots were sectioned horizontally at two levels, perpendicular to the long axis of the block. Pre-and post-instrumentation photographs of each section were taken using a stereomicroscope |