الفهرس 
INTRODUCTIONOnly 14 pages are availabe for public view
 |  | from | 141 |  |  |
| | | from | 141 | | |
Abstract
This study was conducted to evaluate the amount of remaining filing material and apically extruded debris after retreatment using Reciproc Blue, Hyflex EDM and ProTaper Retreatment Files.
Thirty-nine extracted permanent mandibular first molars with moderately curved mesial roots were selected. Mesio-buccal canals were prepared using the ProTaper Next system up to size X2 and filled using gutta-percha and ADseal sealer via cold lateral compaction. Teeth were then randomly divided into three equal groups: group 1: Reciproc Blue, group 2: Hyflex EDM, group 3: ProTaper Universal Retreatment file system+ ProTaper Next file system. Eppendorf tubes were used to collect the apically extruded debris. Cone-beam computed tomographic scans were taken prior to and after retreatment and the volume of remaining obturation material was assessed at the coronal, middle and apical levels.
Data was then recorded and statistically analyzed. The results showed that no statistically significant differences were found among the three groups in either the volume of the remaining obturation material or the weight of the apically ejected debris.
It was concluded that Reciproc Blue R25 file and Hyflex EDM ’One file’ can be used efficiently and safely during retreatment of moderately curved root canals. However, none of the three tested file systems was capable of entirely eliminating the obturation material from the canals or preventing the apical extrusion of debris during retreatment.