Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2023 May;8(3):201-206.
doi: 10.14744/eej.2023.73792.

Dynamic Cyclic Fatigue Resistance of Heat-treated Nickel Titanium Instruments in Reciprocating Motion

Thaís Kauana Magalhães Sobral  1 , Lucila Piasecki  2 , Flávia Sens Fagundes Tomazinho  3 , Alison Luís Kirchhoff  4 , Marilisa Carneiro Leão Gabardo  3 , Natanael Henrique Ribeiro Mattos  5 , Flares Baratto Filho  6 , Luiz Fernando Fariniuk  7
Affiliations

Dynamic Cyclic Fatigue Resistance of Heat-treated Nickel Titanium Instruments in Reciprocating Motion

Thaís Kauana Magalhães Sobral et al. Eur Endod J. 2023 May.

Abstract

Objective: To compare the fatigue resistance of different heat-treated reciprocating instruments tested in a dynamic cyclic fatigue model.

Methods: Forty-eight new instruments were inspected under magnification and selected for this study, and then divided as follows (n=12): X1 Blue (MK Life, Porto Alegre, RS, Brazil), Pro-R (MK Life), Reciproc (VDW, Munich, Germany), and Reciproc Blue (VDW). Artificial canals presenting a curvature of 60° angle and 5 mm radius were milled in zirconia. The block containing the artificial canals was mounted in a container filled with water kept at 37°C. A specially designed device was used to perform controlled axial movements while the instruments were activated inside the canals. Time to failure was recorded in seconds, and fragment lengths were measured (mm). Data were analyzed statistically with the significance level set at 5% (One-Way ANOVA and Tukey test).

Results: Pro-R and Reciproc Blue instruments presented the highest fatigue resistance, being significantly different from the other tested files (p<0.05). Reciproc presented intermediate results, significantly different X1 Blue (p<0.05). The fractographic analysis showed typical features of cyclic fatigue for all instruments.

Conclusion: Pro-R and Reciproc Blue instruments are more resistant to dynamic cyclic fatigue than the Reciproc and X1 Blue. (EEJ-2022-10-124).

PubMed Disclaimer

Conflict of interest statement

The authors deny any conflict of interest.

Figures

FIGURE 1
FIGURE 1
Customized device
FIGURE 2
FIGURE 2
Schematic drawing of the artificial canal
FIGURE 3
FIGURE 3
SEM images showing the cross-section of the fractured instruments at 150× (a-d) and 2500× (e-h) magnification: (a, e) Pro-R; (b, f) Reciproc; (c, g) Reciproc Blue; (d, h) X1 Blue. Higher magnification of images of the fracture surface of the instruments displays specific patterns indicating cyclic fatigue failure SEM: Scanning electron microscopy
See this image and copyright information in PMC

References

    1. Plotino G, Grande NM, Cordaro M, Testarelli L, Gambarini G. A review of cyclic fatigue testing of nickel-titanium rotary instruments. J Endod. 2009;35(11):1469–76. - PubMed
    1. Serene TP, Adams JD, Saxena A. St Louis: Ishiyaku Euro America; 1995. Nickel-titanium Instruments: Applications in Endodontics.
    1. Shen Y, Zhou HM, Zheng YF, Peng B, Haapasalo M. Current challenges and concepts of the thermomechanical treatment of nickel-titanium instruments. J Endod. 2013;39(2):163–72. - PubMed
    1. Sattapan B, Nervo GJ, Palamara JE, Messer HH. Defects in rotary nickel-titanium files after clinical use. J Endod. 2000;26(3):161–5. - PubMed
    1. Gambarini G, Piasecki L, Di Nardo D, Miccoli G, Di Giorgio G, Carneiro E, et al. Incidence of deformation and fracture of twisted file adaptive instruments after repeated clinical use. J Oral Maxillofac Res. 2016;7(4):1–7. - PMC - PubMed

LinkOut - more resources