A Scanning Electron Microscopic Evaluation of SurfaceDefects of New and Used Retreatment Files

This study evaluated the surface defects of new and used Retreatment files using scanning electron microscope. Methods: Thirty extracted human mandibular molars with curvature 10o to 25o were used in the study. The selected teeth decapitated and distal roots were separated then cut coronally to establish 16 mm length. Root canal preparation was performed using ProTaper Rotary system, Obturation was performed with lateral compaction technique using master cone sizeF2 with Resin sealer. The obturated teeth were randomly divided into two main groups of fifteen teeth. In-group I: ten sets of ProTaper retreatment files will be used to remove gutta-percha from thirty obturated canals and in group II: ten sets of D-race retreatment files were used to removegutta-percha from thirty obturated canals. ProTaper and D-race retreatment files were examined before and after being used. Results: scanning electron microscopic analysis of both the retreatment file systems revealed that, the ProTaper retreatment files were less surface defects than the D-Race retreatment files but, the difference was not statistically significant. Conclusion: ProTaper retreatment files showed less distortion and fracture when compared to D-Race retreatment files.