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Updated: May 25, 2026

Scanning Electron Microscopic Evaluation of Surface Defects of Remover Retreatment File After Single and Multiple Uses
Published on: October 11, 2024
The challenge of C-shaped canal systems: a comparative study of the self-adjusting file and ProTaper
Michael Solomonov1, Frank Paqué, Bing Fan
1Department of Endodontics, Hebrew University and Hadassah School of Dental Medicine, Jerusalem, Israel. mishasol@gmail.com
Introduction:
C-shaped canals are anatomic features that present the clinician with both diagnostic and operational challenges. The aim of this study was to compare the efficacy of the Self-Adjusting File (SAF; ReDent, Ra'anana, Israel) in shaping C-shaped canals with that of the rotary ProTaper file system (Dentsply-Maillefer, Ballaigues, Switzerland).
Methods:
Sixteen mandibular second molars and 4 maxillary second molars with C-shaped canals were obtained, originating from native Chinese population. They were divided into 2 equal groups of 10 teeth each, based on similar canal morphology as presented in preliminary micro-computed tomography-derived images. One group was shaped using the SAF, whereas the other was shaped using the ProTaper file system. Reconstructed micro-computed tomographic images before and after treatment were superimposed over each other, and the percentage of the canal wall unaffected by the procedure was calculated. Comparison of the 2 groups for this parameter was performed using the Student t test.
Results:
When treated with the SAF, 41% ± 14% of the canal walls remained unaffected by the procedure, whereas 66% ± 6% of the wall area was unaffected when using ProTaper, which was significantly higher than that of the SAF-treated group (P < .001).
Conclusions:
The SAF was more effective than the ProTaper file system in shaping the walls of C-shaped root canals.
