World Journal of Dentistry

Register      Login

VOLUME 12 , ISSUE 1 ( January-February, 2021 ) > List of Articles


Cyclic Fatigue of TruNatomy Nickel-Titanium Rotary Instrument in Single and Double Curvature Canals: A Comparative Study

Sarah A Rashid, Hikmet A AI-Gharrawi

Keywords : 2Shape, Cyclic fatigue, Double curvature, ProTaper Next, TruNatomy

Citation Information : Rashid SA, AI-Gharrawi HA. Cyclic Fatigue of TruNatomy Nickel-Titanium Rotary Instrument in Single and Double Curvature Canals: A Comparative Study. World J Dent 2021; 12 (1):28-31.

DOI: 10.5005/jp-journals-10015-1793

License: CC BY-NC 4.0

Published Online: 00-02-2021

Copyright Statement:  Copyright © 2021; Jaypee Brothers Medical Publishers (P) Ltd.


Aim: The aim of this study is to measure the cyclic fatigue resistance of TruNatomy (Dentsply Sirona, Maillefer, Ballaigues, Switzerland) instruments in single and double curvature canals and compare it with those of ProTaper Next and 2Shape. Materials and methods: Sixty NiTi rotary files were used in this study and distributed into three groups (n = 20 for each group). Group I: TruNatomy (size 26, taper 0.04), group II: ProTaper Next (size 25, taper 0.06), and group III: 2Shape (size 25, taper 0.06). Then, each group was subdivided into two subgroups (n = 10 for each subgroup) according to the curvature of the canals (single or double). Lengths of all the used files were 25 mm. The files were tested in custom-made artificial canals with a single curvature (60° curvature, 5-mm radius) and a double curvature (coronal curve: 60° curvature, 5-mm radius and apical curve: 70° curvature and 2-mm radius). Each file was operated in a continuous rotation movement until the file fractures. Time for file separation and length of fractured fragment were recorded. The number of cycles to failure of each file was calculated. Statistical analysis: Data were statistically analyzed using the Shapiro-Wilk test, one-way ANOVA, and the post hoc Tukey test. Results: The normal distribution of data was detected by the use of the Shapiro-Wilk test. The results of the ANOVA test revealed a significant difference in cyclic fatigue resistant among three groups of the tested files (p < 0.05). The post hoc Tukey test showed that in both single- and double-curved canals, the number of cycles to failure of the TruNatomy group was significantly higher than other groups (p < 0.05). No statistical difference in fragment length among the tested files in both curvatures (p > 0.05). Conclusion: In both curvatures, TruNatomy instruments were more resistant to cyclic fatigue than 2Shape and ProTaper Next instruments.

PDF Share
  1. Yared G, Kulkarni G. Failure of profile NiTi instruments used by an inexperienced operator under access limitations. Int Endod J 2002;35(6):536–541. DOI: 10.1046/j.1365-2591.2002.00528.x.
  2. Yılmaz K, Uslu G, Özyürek T. In vitro comparison of the cyclic fatigue resistance of HyFlex EDM, One G, and ProGlider nickel titanium glide path instruments in single and double curvature canals. Rest Dent Endod 2017;42(4):282–287. DOI: 10.5395/rde.2017.42.4.282.
  3. Pirani C, Iacono F, Generali L, et al. HyFlex EDM: superficial features, metallurgical analysis and fatigue resistance of innovative electro discharge machined NiTi rotary instruments. Int Endod J 2016;49(5):483–493. DOI: 10.1111/iej.12470.
  4. Ataya M, Hong J, Kwak S, et al. Mechanical properties of orifice preflaring nickel-titanium rotary instrument heat treated using T-wire technology. JOE 2018;44(12):1867–1871. DOI: 10.1016/j.joen.2018.08.016.
  5. Huang X, Shen Y, Wei X, et al. Fatigue resistance of nickel-titanium instruments exposed to high-concentration hypochlorite. JOE 2017;43(11):1847–1851. DOI: 10.1016/j.joen.2017.06.033.
  6. Dentsply Sirona. TruNatomy Brochure. Available at: https://www. Accessed April 26, 2019.
  7. Gündoğar M, Uslu G, Özyürek T, et al. Comparison of the cyclic fatigue resistance of VDW.ROTATE, TruNatomy, 2Shape, and HyFlex CM nickel-titanium rotary files at body temperature. Restor Dent Endod 2020;45(3):e37. DOI: 10.5395/rde.2020.45.e37.
  8. Van der Vyver PJ, Vorster M, Peters OA. Minimally invasive endodontics using a new single-file rotary system. Int Dent – African ed 2019;9(4):6–20.
  9. Al-Sudani D, Grande NM, Plotino G, et al. Cyclic fatigue of nickel-titanium rotary instruments in a double (S-shaped) simulated curvature. J Endod 2012;38(7):987–989. DOI: 10.1016/j.joen.2012.03.025.
  10. Larsen C, Watanabe I, Glickman G. Cyclic fatigue analysis of a new generation of nickel titanium rotary instruments. J Endod 2009;35(3):401–403. DOI: 10.1016/j.joen.2008.12.010.
  11. Pedulla E, Grande N, Plotino G, et al. Influence of continuous or reciprocating motion on cyclic fatigue resistance of 4 different nickel-titanium rotary instruments. JOE 2013;39(2):258–261. DOI: 10.1016/j.joen.2012.10.025.
  12. Plotino G, Grande N, Melo M, et al. Cyclic fatigue of NiTi rotary instruments in a simulated apical abrupt curvature. Int Endod J 2010;43(3):226–230. DOI: 10.1111/j.1365-2591.2009.01668.x.
  13. Bhagabati N, Yadav S, Talwar S. An in vitro cyclic fatigue analysis of different endodontic nickel-titanium rotary instruments. JOE 2012;38(4):515–518. DOI: 10.1016/j.joen.2011.12.034.
  14. Mohammed A, Al-zaka I. Cyclic fatigue of different glide path systems in single and double curved simulated canal: a comparative study. Int J Med Res Health 2018;7(11):72–78.
  15. Haapasalo M, Udnaes T, Endal U. Persistent, recurrent, and acquired infection of the root canal system posttreatment. Endodontic Topics 2003;6(1):29–56. DOI: 10.1111/j.1601-1546.2003.00041.x.
  16. Yao J, James H, Scott A, et al. Cyclic fatigue of three types of rotary nickel titanium files in a dynamic model. J Endod 2006;32(1):55–57. DOI: 10.1016/j.joen.2005.10.013.
  17. Pedullà E, Lo Savio F, Boninelli S, et al. Torsional and cyclic fatigue resistance of a new nickel-titanium instrument manufactured by electrical discharge machining. J Endod 2016;42(1):156–159. DOI: 10.1016/j.joen.2015.10.004.
  18. Topcuoğlu H, Topcuoğlu G, Kafdağ Ö, et al. Cyclic fatigue resistance of new reciprocating glide path files in 45‐and 60‐degree curved canals. Int Endod J 2018;51(9):1053–1055. DOI: 10.1111/iej.12915.
  19. Abe A, Varghese N, Pillai R, et al. Resistance to torsional failure and cyclic fatigue resistance of ProTaper next, WaveOne, and Mtwo files in continuous and reciprocating motion: an in vitro study. J Conserv Dent 2016;19(3):225–230. DOI: 10.4103/0972-0707.181937.
  20. Özyürek T, Gündoğar M, Uslu G, et al. Cyclic fatigue resistances of Hyflex EDM, WaveOne gold, reciproc blue and 2shape NiTi rotary files in different artificial canals. Odontology 2018;106(4):408–413. DOI: 10.1007/s10266-018-0340-y.
  21. Melo M, Pereira E, Viana A, et al. Dimensional characterization and mechanical behaviour of K3 rotary instruments. Int Endod J 2008;41(4):329–338. DOI: 10.1111/j.1365-2591.2007.01368.x.
  22. Riyahi A, Bashiri A, Alshahrani K, et al. Cyclic fatigue comparison of TruNatomy, Twisted file, and ProTaper next rotary systems. Int J Dent 2020;2020:3190938. DOI: 10.1155/2020/3190938.
  23. Elnaghy A, Elsaka S. Cyclic fatigue resistance of one curve, 2Shape, ProFile vortex, vortex blue, and RaCe nickel-titanium rotary instruments in single and double curvature canals. J Endod 2018;44(11):1725–1730. DOI: 10.1016/j.joen.2018.07.023.
  24. Higuera O, Plotino G, Tocci L, et al. Cyclic fatigue resistance of 3 different nickel -titanium reciprocating instruments in artificial canals. JOE 2015(41):913–915. DOI: 10.1016/j.joen.2015.01.023.
  25. Vadhana S, SaravanaKarthikeyan B, Nandini S, et al. Cyclic fatigue resistance of RaCe and Mtwo rotary files in continuous rotation and reciprocating motion. JOE 2014;7(40):995–999. DOI: 10.1016/j.joen.2013.12.010.
PDF Share

© Jaypee Brothers Medical Publishers (P) LTD.