Fatigue Behavior of Ni-Ti Alloy Endodontic Files under Ultrasonic Unconstrained Condition
| Periodical | Key Engineering Materials (Volumes 417 - 418) |
|---|---|
| Main Theme | Advances in Fracture and Damage Mechanics VIII |
| Edited by | M.H Aliabadi, S. Abela, S. Baragetti, M. Guagliano and Han-Seung Lee |
| Pages | 77-80 |
| DOI | 10.4028/www.scientific.net/KEM.417-418.77 |
| Citation | Hui Min Zhou et al., 2009, Key Engineering Materials, 417-418, 77 |
| Online since | October, 2009 |
| Authors | Hui Min Zhou, Qing Fen Li, Yu Feng Zheng, Li Li |
| Keywords | Endodontic File, Fatigue Behaviour, NiTi Alloy, Ultrasonic Condition |
| Price | US$ 28,- |
Nickel-titanium alloy are extensively used in engineering and biomedical fields for their excellent properties of shape-memory, super-elasticity and biocompatibility. Their fatigue performance has been attracted increasingly attention, because they are often used under cyclic conditions. In this paper, the ultrasonic fatigue behavior of nickel-titanium endodontic files under unconstrained condition has been studied using the self-designed ultrasonic fatigue testing equipment. The vibration and harmonious response properties of nickel-titanium endodontic files are also analyzed using finite element method. Experimental results show that the average ultrasonic fatigue life of nickel-titanium endodontic files under unconstrained conditions is more than 108. Fracture of the files always occurred at the position about 2 -3 mm near the file tip. Results of finite element analysis show that the maximum stress of the nickel-titanium endodontic files located at the position about 2 -3 mm near the file tip, where is prone to generate fatigue cracks. The results of finite element analysis are consistent with the experimental results. The scanning electronic microscope (SEM) results show that the ultrasonic fatigue cracks always initiated at the surfaces of the files, where the secondary phases or impurities existed and induced fatigue cracks under repeated stress.
