Comparison of mechanical properties of nickel-titanium rotary files: Aurum Blue vs. Aurum Pro

Kwak,  Sang Won; Ha,  Jung-Hong; Ahn,  Sang Mi; Kim,  Hyeon-Cheol

J Korean Dent Assoc > Volume 57(11); 2019 > Article

The Journal of The Korean Dental Association 2019;57(11):672-678.
Published online November 30, 2019.

니켈티타늄 전동 파일의 기계적 특성 비교: Aurum Blue vs. Aurum Pro

곽상원¹, 하정홍², 안상미³, 김현철⁴

^¹부산대학교 치의학전문대학원 치과보존학교실
^²경북대학교 치과대학 치과보존학교실
^³부산대학교 치의학전문대학원 치과보존학교실
^⁴부산대학교 치의학전문대학원 치과보존학교실

Comparison of mechanical properties of nickel-titanium rotary files: Aurum Blue vs. Aurum Pro

Sang Won Kwak¹, Jung-Hong Ha², Sang Mi Ahn³, Hyeon-Cheol Kim⁴

¹Department of Conservative Dentistry, School of Dentistry, Dental Research Institute, Pusan National University
²Department of Conservative Dentistry, School of Dentistry, Kyungpook National University
³Department of Conservative Dentistry, School of Dentistry, Dental Research Institute, Pusan National University
⁴Department of Conservative Dentistry, School of Dentistry, Dental Research Institute, Pusan National University

Abstract

AIM
The purpose of this study was to evaluate and compare the torsional fracture resistances, cyclic fatigue resistance, and bending stiffness of two nickel-titanium (NiTi) rotary instruments made of different heat-treated alloy: Aurum Blue (heat-treated) and Aurum Pro (conventional). Methods: Forty-five Aurum Blue and Aurum Pro NiTi files were selected for the three mechanical tests (n=15). For the torsional resistance test, 3 mm file tip was fixed and the shaft was driven clockwise at 2 rpm until fracture occurred by using a customized device. Cyclic fatigue resistance was evaluated by rotating instruments in artificial canal with dynamic mode. Bending stiffness was tested by observation of the bending moment on attaining a 45° bend. The results were analyzed by student-t tests at a significance level of 95%. The fractured surface of each groups were examined under a scanning electron microscope (SEM). Results: Aurum Blue showed significantly higher toughness, ultimate strength, distortion angle, and number of cycles to failure than those of Aurum Pro (p < 0.05). However, Aurum Blue and Aurum Pro did not differ significantly in terms of bending stiffness. SEM showed typical topographic appearances of the cyclic fatigue and torsional fracture. Conclusions: Under the limitations of this study, heat-treated instruments showed higher flexibility and fracture resistances than conventional NiTi instruments.

Key Words: Endodontic treatment;Nickel-titanium file;Torsional resistance;Cyclic fatigue resistance;Bending stiffness;CM-wire;