Metallurgic behavior and mechanical property of nickel-titanium endodontic files made by 3 heat treatment techniques
10.3760/cma.j.issn.1002-0098.2018.08.008
- VernacularTitle: 三种特殊热处理技术对镍钛根管锉相变行为、弯曲性能和抗疲劳折断性能影响的研究
- Author:
Yinjie YANG
1
;
Benxiang HOU
2
;
Xiaomei HOU
3
Author Information
1. Second Clinical Division, Peking University School and Hospital of Stomatology & National Clinical Research Center for Oral Diseases & National Engineering Laboratory for Digital and Material Technology of Stomatology & Beijing Key Laboratory of Digital Stomatology, Beijing 100101, China (Present address: Department of Stomatology, Beijing Xicheng District Xinjiekou Community Health Service Center, Beijing 100053, China)
2. Department of Endodontics and Operative Dentistry, Capital Medical University School of Stomatology, Beijing 100050, China
3. Second Clinical Division, Peking University School and Hospital of Stomatology & National Clinical Research Center for Oral Diseases & National Engineering Laboratory for Digital and Material Technology of Stomatology & Beijing Key Laboratory of Digital Stomatology, Beijing 100101, China
- Publication Type:Journal Article
- Keywords:
Root canal preparation;
Phase transition;
Nickel-titanium file;
Bending property;
Cyclic fatigue
- From:Chinese Journal of Stomatology
2018;53(8):539-545
- CountryChina
- Language:Chinese
-
Abstract:
Objective:To compare the phase transformation behavior, bending property and cyclic fatigue resistance of CM-wire, R-phase and M-wire nickel-titanium endodontic files treated by 3 heat treatment techniques.
Methods:Hyflex CM (25 mm, 25#/0.06) made from CM wire, TF (25 mm, 25#/0.06) made from R-phase heat treatment, ProTaper Next X2 (25 mm, tip size 25#/0.06) made from M-wire, Mtwo (25 mm, 25#/0.06) and ProTaper F2 (25 mm, tip size 25#/0.08) made from conventional nickel-titanium wire were chosen. Five of each files were chosen for differential scanning calorimetric (DSC) evaluation (n=5). The specimens were prepared from adjacent portions of the shaft. The weight and length were typically (20±1) mg and 2-3 mm. Another eight of the 5 nickel-titanium files were undergone cantilever-bending test, respectively (n=8). Further ten of the 5 instruments were submitted to the cyclic fatigue test by using a simulated metal root canal (n=10). The data of Ms, Mf, As, Af, ΔH, bending load, number of cyclic fatigue (NCF), fragment length were analyzed using one-way analysis of variance at a significance level of P<0.05.
Results:The Af of Hyflex CM [(60.27±0.94) ℃] and ProTaper Next [(51.40±0.32) ℃] were higher than body temperature of 37 ℃. The bending load values at 3.0 mm deflection of Hyflex CM [(0.867±0.074) N], TF [(1.275±0.146) N], Mtwo [(2.281±0.426) N], ProTaper Next [(3.104±0.252) N] and ProTaper [(4.227±0.483) N] increased gradually and significantly. The NCF of Hyflex CM (582±99), TF (427±85), ProTaper Next (158±22), Mtwo (129±32) and ProTaper (65±20) decreased gradually.
Conclusions:The 3 heat treatment techniques exert tremendous influence on the phase transformation behavior and mechanical characteristics of the files, which demonstrate improved bending property and cyclic fatigue resistance than the conventional ones.
