الفهرس 
Introduction
Shaping abilityOnly 14 pages are availabe for public view
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Abstract
The aim of this study was to evaluate the applicability of reciprocating the (SU) file of the Revo-S set by comparing
it with the classical Revo-S technique regarding its shaping ability via assessment of canal centering ability and canal curvature as well as its cleaning efficiency via assessment of the percentage of surface area covered in debris.
The percentage of change in canal curvature, the Mesiodistal transportation and Mesio-distal centering ability were assessed by comparing pre- and post- instrumentation
measurements taken on CBCT images, while the canal cleanliness was evaluated using the stereomicroscope.
A total of forty eight human permanent mandibular molars were used in this study. Access cavities were done; then special measures were taken to ensure standardization and reproducibility of CBCT images.
Samples were divided into two groups according to the instrumentation motion; Conventional Revo-S system in
continuous rotation (group I) and the proposed technique of single SU file in an unbalanced reciprocation motion (group II). Each group was further divided into three subgroups (subgroup A, subgroup B and subgroup C) according to the number of uses of the file.
Shaping ability assessment using CBCT images analysis:
Change in canal curvature was assessed by comparing pre- and post- CBCT images in the sagittal sections while measurements to assess Mesio-distal transportation and centering ability were taken on the axial sections at three levels (2,5 and 8 mm). Data were collected then statistical analysis was performed.
Canal cleanliness assessment:
Longitudinal sections were photographed using the stereomicroscope then images were analyzed using image J software to measure the percentage of the surface area covered in debris at the coronal, middle and apical thirds.
Data were collected and statistically analyzed.
Results:
Concerning the change in canal curvature and canal cleanliness, the results showed no statistically significant difference between the proposed technique and the conventional one.
Concerning Mesio-distal transportation and centering ability the results showed very comparable results that
always favored the proposed technique when statistically significant results were recorded.