Effect of surface treatment on the mechanical properties of nickel-titanium files with a similar cross-section.
10.5395/rde.2017.42.3.216
- Author:
Sang Won KWAK
1
;
Joo Yeong LEE
;
Hye Jin GOO
;
Hyeon Cheol KIM
Author Information
1. Department of Conservative Dentistry, Pusan National University School of Dentistry and Dental Research Institute, Yangsan, Korea. golddent@pusan.ac.kr
- Publication Type:Original Article
- Keywords:
Cross-section;
Cyclic fatigue;
Nickel-titanium file;
Surface treatment;
Torsional strength
- MeSH:
Fatigue
- From:Restorative Dentistry & Endodontics
2017;42(3):216-223
- CountryRepublic of Korea
- Language:English
-
Abstract:
OBJECTIVES: The aim of this study was to compare the mechanical properties of various nickel-titanium (NiTi) files with similar tapers and cross-sectional areas depending on whether they were surface-treated. MATERIALS AND METHODS: Three NiTi file systems with a similar convex triangular cross-section and the same ISO #25 tip size were selected for this study: G6 (G6), ProTaper Universal (PTU), and Dia-PT (DPT). To test torsional resistance, 5 mm of the straightened file's tip was fixed between polycarbonate blocks (n = 15/group) and continuous clockwise rotation until fracture was conducted using a customized device. To evaluate cyclic fatigue resistance, files were rotated in an artificial curved canal until fracture in a dynamic mode (n = 15/group). The torsional data were analyzed using 1-way analysis of variance and the Tukey post-hoc comparison test, while the cyclic fatigue data were analyzed using the Mann-Whitney U test at a significance level of 95%. RESULTS: PTU showed significantly greater toughness, followed by DPT and G6 (p < 0.05). G6 showed the lowest resistance in ultimate torsional strength, while it showed a higher fracture angle than the other files (p < 0.05). In the cyclic fatigue test, DPT showed a significantly higher number of cycles to failure than PTU or G6 (p < 0.05). CONCLUSIONS: Within the limitations of this study, it can be concluded that the torsional resistance of NiTi files was affected by the cross-sectional area, while the cyclic fatigue resistance of NiTi files was influenced by the surface treatment.
