Related Experiment Video
Updated: Jul 14, 2026
Scanning Electron Microscopic Evaluation of Surface Defects of Remover Retreatment File After Single and Multiple Uses
Published on: October 11, 2024
A scanning electron microscopy evaluation of microfractures, deformation and separation in EndoSequence and Profile
Keven S Herold1, Bradford R Johnson, Christopher S Wenckus
1Department of Endodontics, University of Illinois at Chicago, Chicago, Illinois 60612, USA.
Abstract:
The development of microfractures in the EndoSequence nickel-titanium rotary (NTR) file (Brassler USA, Savannah, GA) and Profile NTR file was evaluated by using scanning electron microscopy (SEM). Seventy-three maxillary buccal roots and 53 mandibular mesial roots with an average canal curvature of 37 degrees were randomly assigned to one of three groups and prepared with 21-mm .06 taper NTR files as follows: (1) EndoSequence at 300 rpm, (2) EndoSequence at 600 rpm, and (3) ProFile at 300 rpm. File sizes .45 to .20 were used in a crown-down technique to a master apical file (MAF) size of .35/.06. The MAF instruments were evaluated by SEM before use, after completion of 7 canals, and after completion of 14 canals. All EndoSequence instruments developed microfractures by the seven-canal evaluation. The ProFile instruments showed no microfractures at the 7- or 14-canal evaluations. EndoSequence files separated at a higher rate than ProFile instruments. Under the conditions of this study, unique file design and electropolishing did not inhibit the development of microfractures in EndoSequence NTR.
