Cyclic fatigue resistance of D-RaCe, ProTaper, and Mtwo nickel–titanium retreatment instruments after immersion in sodium hypochlorite

ABSTRACT The aim of this in vitro study was to compare the cyclic fatigue resistance of three single-use nickel-titanium (NiTi) instruments (One Shape, Reciproc and Wave One) after immersion in sodium hypochlorite (NaOCl) solution over several time periods. A total of 135 One Shape, Reciproc R25 and Wave One Primary were tested. The 45 files of the same brand were randomly assigned to three groups (n = 15) and submitted to the following immersion protocol: 1 minute in 5% NaOCl at 37°C, 5 minutes in 5% NaOCl at 37°C, no immersion (as control). Cyclic fatigue test was performed rotating/reciprocating all instruments in a stainless steel curved artificial canal (60° angle of curvature and 5 mm radius). The number of cycles to fracture (NCF) was determined by measuring the time to fracture. The data were compared for differences by using 2-way analysis of variance (p < 0.05). In general, resistance to cyclic fatigue was not significantly affected by immersion in NaOCl. Reciproc R2 showed the highest cyclic fatigue resistance in all groups compared to One Shape and Wave One. Immersion in NaOCl for 1 or 5 minutes did not reduce the cyclic fatigue resistance of NiTi single-use instruments significantly. Reciproc were more resistant, but the new rotary single-use One Shape instruments showed mechanical resistance similar to NiTi files developed for reciprocating motion. How to cite this article Dagna A, Beltrami R, Colombo M, Chiesa M, Bianchi S, Poggio C. Cyclic Fatigue Resistance of Three Single-use NiTi Instruments after Immersion in Sodium Hypochlorite. Int J Experiment Dent Sci 2014;3(2):67-72.

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Effect of sodium hypochlorite on the cyclic fatigue resistance: A scanning electron microscopy evaluation

Microscopy Research and Technique ◽

10.1002/jemt.23381 ◽

2019 ◽

Vol 82 (12) ◽

pp. 2089-2094 ◽

Cited By ~ 5

Author(s):

İhsan F. Ertuğrul

Keyword(s):

Electron Microscopy ◽

Scanning Electron Microscopy ◽

Fatigue Resistance ◽

Sodium Hypochlorite ◽

Cyclic Fatigue ◽

Scanning Electron Microscopy Evaluation ◽

Scanning Electron

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Effect of synchronous irrigation on cyclic fatigue of nickel-titanium instrument in the dynamic and static models

Journal of Applied Biomaterials & Functional Materials ◽

10.1177/2280800020987403 ◽

2021 ◽

Vol 19 ◽

pp. 228080002098740

Author(s):

Haiyun Liu ◽

Yanfeng Li ◽

Guangquan Chai ◽

Yuan Lv ◽

Changjian Li ◽

...

Keyword(s):

Fatigue Resistance ◽

Flow Rate ◽

Dynamic Control ◽

Cyclic Fatigue ◽

Nickel Titanium ◽

Control Group ◽

Time To Failure ◽

Dynamic Tests ◽

Significant Difference ◽

Experimental Group

Objective: To evaluate the effect of synchronous water irrigation on the fatigue resistance of nickel-titanium instrument. Methods: A standardized cyclic fatigue test models were established, and five types of nickel-titanium instruments (PTU F1, WO, WOG, RE, and M3) were applied. Each instrument was randomly divided into two groups ( N = 12). There was synchronous water irrigation in the experimental group, and no water irrigation in the control group. Besides, ProTaper Universal F1 was randomly divided into 10 groups ( N = 20). In the static group, nickel-titanium instruments were divided into one control group (no irrigation, N = 20) and six experimental group (irrigation, N = 20) based on different flow rate, angle and position; while in the dynamic group, instruments were divided into one control group (no irrigation, N = 20) and two experimental group (irrigation, N = 20) based on different flow rate. The rotation time (Time to Failure, TtF) of instruments was recorded and analyzed. Results: According to the static experiments, the TtF of instruments in all experimental groups was significantly higher than that in the static control group. Besides, the dynamic tests of PTU F1 showed that the TtF in the experimental group was significantly higher than that in the dynamic control group. Compared with control group, the TtF in the experimental groups increased by at least about 30% and up to 160%. The static and dynamic tests of PTU F1 showed that the TtF of nickel-titanium instrument in all experimental groups was significantly higher than that in the control group. However, there was no significant difference between any two experimental groups. Conclusion: Regardless of dynamic or static model, TtF with irrigation was longer than that with non-irrigation, indicating that synchronous irrigation can increase the fatigue resistance of nickel-titanium instrument. However, different irrigation conditions may have the same effect on the fatigue resistance.

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