Cyclic Fatigue Evaluation of Nickel-Titanium Rotary Instruments Using an Electrical Resistance-based Method

IF 3.6 2区医学 Q1 DENTISTRY, ORAL SURGERY & MEDICINE

Journal of endodontics Pub Date : 2025-10-01 DOI:10.1016/j.joen.2025.06.015

Congyu Yang BDSc, Yi Min BDSc, MSc, PhD, Wei Fan BDSc, MSc, PhD

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引用次数: 0

Abstract

Introduction

This in vitro study aimed to establish the correlation between electrical resistance and cyclic fatigue of endodontic nickel-titanium (NiTi) rotary instruments as a quantifiable cyclic fatigue indicator.

Methods

Two kinds of geometrically identical NiTi rotary instruments ProTaper Universal F2 and ProTaper Gold F2 were selected and allocated into 2 experimental groups: a cyclic fatigue test group and a sterilization test group. In the cyclic fatigue test group, instruments were rotated in an artificial root canal until fracture, with the number of cycles (rotations) to fracture (NCF) recorded. In the sterilization test group, instruments were rotated to 20%, 40%, 60%, and 80% of the NCF, followed by autoclaving sterilization. Electrical resistance was measured after each 10 rotations, as well as pre- and post-sterilization. Scanning electron microscopy was applied to analyze the instrument surfaces, focusing on the expanding of microcracks over rotations and the effect of autoclaving. The collected data were then statistically analyzed.

Results

The results indicated that the electrical resistance of tested instruments increased quadratically with the cyclic fatigue degrees along with the expanding of microcracks. At the 80% NCF, the electrical resistance increased by 2.38% and 2.63% for PTU F2 and PTG F2 respectively. Autoclaving had no significant effect on electrical resistance.

Conclusion

Electrical resistance could be used as a quantifiable indicator to evaluate and predict the cyclic fatigue degree of NiTi rotary instruments and seems unaffected by autoclaving.

查看原文本刊更多论文

基于电阻法的镍钛旋转仪器循环疲劳评价。

本体外研究旨在建立镍钛（NiTi）根管旋转器械的电阻与循环疲劳的相关性，并将其作为可量化的循环疲劳指标。方法：选用两种几何形状相同的NiTi旋转仪器ProTaper Universal (PTU) F2和ProTaper Gold (PTG) F2分为两个实验组：循环疲劳试验组和灭菌试验组。在循环疲劳试验组，器械在人工根管内旋转至断裂，记录循环（旋转）至断裂（NCF）次数。灭菌试验组分别将仪器旋转至NCF的20%、40%、60%和80%，然后进行高压灭菌。每10次旋转后测量电阻，以及灭菌前后的电阻。利用扫描电子显微镜（SEM）对仪器表面进行了分析，重点研究了微裂纹在旋转过程中的扩展和高压灭菌的影响。然后对收集到的数据进行统计分析。结果：随着微裂纹的扩展，被测仪器的电阻随循环疲劳程度的增加呈二次增长。在80% NCF下，PTU F2和PTG F2的电阻分别增加了2.38%和2.63%。高压灭菌对电阻无显著影响。结论：电阻可作为评价和预测NiTi旋转仪器循环疲劳程度的量化指标，且不受高压灭菌的影响。

本文章由计算机程序翻译，如有差异，请以英文原文为准。

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来源期刊

Journal of endodontics 医学-牙科与口腔外科

CiteScore

8.80

自引率

9.50%

发文量

224

审稿时长

42 days

期刊介绍： The Journal of Endodontics, the official journal of the American Association of Endodontists, publishes scientific articles, case reports and comparison studies evaluating materials and methods of pulp conservation and endodontic treatment. Endodontists and general dentists can learn about new concepts in root canal treatment and the latest advances in techniques and instrumentation in the one journal that helps them keep pace with rapid changes in this field.