Evaluation of the Reciprocation Technique of Single (SU) File Versus the Conventional Rotary Sequence of the Revo-S Files in Curved Root Canals (An In Vitro Study)

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 Mesio-distal 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.