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Updated: Jun 17, 2026
03:07
Scanning Electron Microscopic Evaluation of Surface Defects of Remover Retreatment File After Single and Multiple Uses
Published on: October 11, 2024
Microstructure alterations of rotary files after multiple simulated operative procedures
Arlinda Luzi1, Leopoldo Forner, Amelia Almenar
1Department of Stomatology, Universitat de València, Valencia, Spain.
Medicina Oral, Patologia Oral Y Cirugia Bucal
|December 30, 2009
Summary
ProTaper NiTi files showed significant wear, including cutting edge defects and fatigue cracks, after shaping 30 root canals. Despite these alterations, the ProTaper instruments remain reliable when used correctly.
Area of Science:
- Endodontics
- Materials Science
Background:
- Nickel-titanium (NiTi) rotary instruments are widely used in endodontic procedures.
- Assessing the long-term durability and potential defects of these instruments is crucial for clinical safety and efficacy.
Purpose of the Study:
- To evaluate the morphological changes in ProTaper rotary nickel-titanium (NiTi) files after continuous clinical use.
- To identify specific types of defects that occur on these instruments.
Main Methods:
- Scanning electron microscopy (SEM) was employed to examine ProTaper files before and after shaping 30 root canals.
- Files were used with sodium hypochlorite (NaOCl) irrigation and sterilized between uses.
- Defect analysis included blunt cutting edges, edge disruption, microfractures, fatigue cracks, metal flash, and dentine debris.
Main Results:
- Significant wear was observed, with cutting edge breaks affecting up to 70% of files and fatigue cracks present in 33-100% of files.
- No microfractures were detected in the examined files.
- One S1 and one SX file experienced fracture during the study.
Conclusions:
- ProTaper instruments demonstrate considerable reliability under standard clinical usage conditions.
- Regular inspection for defects like cutting edge wear and fatigue cracks is recommended for safe endodontic practice.
