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VOLUME 22 , ISSUE 11 ( November, 2021 ) > List of Articles


Comparison of Cyclic Fatigue Resistance of Novel TruNatomy Files with Conventional Endodontic Files: An In Vitro SEM Study

Bharath Naga Reddy, Sabari Murugesan, Syed Nahid Basheer, Rajeswary Kumar, Vinoth Kumar, Saravanan Selvaraj

Keywords : Canal curvature, Cyclic fatigue, Dynamic, Heat treatment, HyFlex EDM, ProTaper gold, Reciproc blue, TruNatomy

Citation Information : Reddy BN, Murugesan S, Basheer SN, Kumar R, Kumar V, Selvaraj S. Comparison of Cyclic Fatigue Resistance of Novel TruNatomy Files with Conventional Endodontic Files: An In Vitro SEM Study. J Contemp Dent Pract 2021; 22 (11):1243-1249.

DOI: 10.5005/jp-journals-10024-3177

License: CC BY-NC 4.0

Published Online: 24-02-2022

Copyright Statement:  Copyright © 2021; The Author(s).


Aim and objective: To compare and analyze the cyclic fatigue resistance of novel TruNatomy files against the conventionally used rotary files and reciprocating files in a simulated canal system with curvatures in the middle, apical portions root, and S-shaped canal employing scanning electron microscopy. Materials and methods: Endodontic files tested in the study include ProTaper, HyFlex EDM, Reciproc blue, and TruNatomy files operated in a simulated root canal system. A total of 96 files were employed in this study. They were categorized into four groups. Group 1 employed 24 TruNatomy files, group 2 employed 24 ProTaper gold files, group 3 employed 24 HyFlex EDM files, and group 4 employed 24 Reciproc blue files. All the groups employed eight files each under three subgroups namely A, B, and C representing middle, apical, and double curvatures, respectively. Artificial grooves were incorporated in the stainless steel blocks having three different curvatures. All the file systems were operated with a torque-controlled electric motor. The files were engaged in the artificial canal until the occurrence of fracture. The time required for the fracture was noted. Length of fractured tip was measured using the digital Vernier caliper. The number of cycles of failure (NCF) was calculated. The fractured parts were subjected to scanning electron microscope to analyze the mode of fracture. Results: TruNatomy files had the highest mean NCF values of 588.01 in middle curvature, 1,321 in apical curvature, and 642.5 in S-shaped curvature HyFlex EDM and Reciproc blue file system exhibited comparable cyclic fatigue resistance among them. ProTaper gold file system exhibited least mean NCF values of 158.13 in the middle, 196.5 in the apical curvature, and 116.88 in the S-shaped canal system. Middle portion fractured first than the apical curvature. The mean length of fractured segments was found to be insignificant among the experimental study groups tested. Conclusion: All the file systems employed in the study had good cyclic fatigue resistance while TruNatomy files had the highest cyclic fatigue resistance while HyFlex EDM and Reciproc blue had comparable fatigue resistance. ProTaper gold file system had the least fatigue resistance at different radius of curvature in the simulated canal system in the apical and middle portions and S-shaped root canal. Clinical significance: The selection of file systems in cleaning and shaping protocols is an enigma to the endodontics. This in vitro study explored the selection protocols for the execution of root canal preparation. Heat treatment of nickel–titanium (NiTi) endodontic files had improved the cyclic fatigue résistance significantly enhancing the clinical life of file systems.

  1. Uygun AD, Unal M, Falakaloglu S, et al. Comparison of the cyclic fatigue resistance of hyflex EDM, vortex blue, protaper gold, and onecurve nickel–titanium instruments. Niger J Clin Pract 2020;23(1):41. DOI: 10.4103/njcp.njcp_343_19.
  2. Kaval ME, Capar ID, Ertas H. Evaluation of the cyclic fatigue and torsional resistance of novel nickel-titanium rotary files with various alloy properties. J Endod 2016;42(12):1840–1843. DOI: 10.1016/j.joen.2016.07.015.
  3. Gambarini G, Grande NM, Plotino G, et al. Fatigue resistance of engine-driven rotary nickel-titanium instruments produced by new manufacturing methods. J Endod 2008;34(8):1003–1005. DOI: 10.1016/j.joen.2008.05.007.
  4. Tewari RK, Kapoor B, Kumar A, et al. Fracture of rotary nickel titanium instruments. J Oral Res Rev 2017;9(1):37. DOI: -10.4103/jorr.jorr_40_16.
  5. Rubini AG, Sannino G, Pongione G, et al. Influence of file motion on cyclic fatigue of new nickel titanium instruments. Ann Stomatol 2013;4(1):149. DOI: 10.11138/ads.0149
  6. Pedullà E, Grande NM, Plotino G, et al. Influence of continuous or reciprocating motion on cyclic fatigue resistance of 4 different nickel-titanium rotary instruments. J Endod 2013;39(2):258–261. DOI: 10.1016/j.joen.2012.10.025.
  7. Elsewify TM, Saber SM, Plotino G. Cyclic fatigue resistance of three heat-treated nickel-titanium instruments at simulated body temperature. Saudi Endod J 2020;10(2):131. DOI: 10.4103/sej.sej_122_19
  8. Plotino G, Grande NM, Testarelli L, et al. Cyclic fatigue of Reciproc and Reciproc Blue nickel-titanium reciprocating files at different environmental temperatures. J Endod 2018;44(10):1549–1552. DOI: 10.1016/j.joen.2018.06.006.
  9. Khandagale PD, Shetty PP, Makandar SD, et al. Evaluation of cyclic fatigue of hyflex EDM, twisted files, and protaper gold manufactured with different processes: an in vitro study. Int J Dent 2021;2021:7402658. DOI: 10.1155/2021/7402658.
  10. Al-Obaida MI, Merdad K, Alanazi MS, et al. Comparison of cyclic fatigue resistance of 5 heat-treated nickel-titanium reciprocating systems in canals with single and double curvatures. J Endod 2019;45(10):1237–1241. DOI: 10.1016/j.joen.2019.06.011.
  11. 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). DOI: 10.5395/rde.2020.45.e37.
  12. La Rosa GR, Shumakova V, Isola G, et al. Evaluation of the cyclic fatigue of two single files at body and room temperature with different radii of curvature. Materials 2021;14(9):2256. DOI: 10.3390/ma14092256.
  13. Haikel Y, Serfaty R, Bateman G, et al. Dynamic and cyclic fatigue of engine-driven rotary nickel-titanium endodontic instruments. J Endod 1999;25(6):434–440. DOI: 10.1016/S0099-2399(99)80274-X.
  14. Grande NM, Plotino G, Pecci R, et al. Cyclic fatigue resistance and three-dimensional analysis of instruments from two nickel–titanium rotary systems. Int Endod J 2006;39(10):755–763. DOI: 10.1111/j.1365-2591.2006.01143.x.
  15. Pedullà E, Savio FL, 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.
  16. Parashos P, Messer HH. Rotary NiTi instrument fracture and its consequences. J Endod 2006;32(11):1031–1043. DOI: 10.1016/j.joen.2006.06.008.
  17. Pirani C, Cirulli PP, Chersoni S, et al. Cyclic fatigue testing and metallographic analysis of nickel-titanium rotary instruments. J Endod 2011;37(7):1013–1016. DOI: 10.1016/j.joen.2011.04.009.
  18. Zupanc J, Vahdat-Pajouh N, Schäfer E. New thermomechanically treated NiTi alloys – a review. Int Endod J 2018;51(10):1088–1103. DOI: 10.1111/iej.12924.
  19. Piț AB, Borcean IA, Vărgatu IA, et al. Evaluation of the time and efficiency of trunatomy, VDW. Rotate, protaper gold and reciproc blue in shaping root canals – an in vitro study. Roman J Oral Rehabil 2020;12(3):250. DOI: 12.1011/rjor.2020.043.
  20. Oh S, Kum KY, Kim HJ, et al. Bending resistance and cyclic fatigue resistance of WaveOne Gold, Reciproc Blue, and HyFlex EDM instruments. J Dent Sci 2020;15(4):472–478. DOI: 10.1016/j.jds.2019.10.003.
  21. Özyürek T, Gündoğar M, Yılmaz K, et al. Bending resistance and cyclic fatigue life of Reciproc Blue, WaveOne Gold, and Genius files in a double (S-shaped) curved canal. J Dent Res Dent Clin Dent Prospects 2017;11(4):241. DOI: 10.15171/joddd.2017.042.
  22. Uslu G, Gundogar M, Özyurek T, et al. Cyclic fatigue resistance of reduced-taper nickel-titanium (NiTi) instruments in doubled-curved (S-shaped) canals at body temperature. J Dent Res Dent Clin Dent Prospects 2020;14(2):111. DOI: 10.34172/joddd.2020.024.
  23. Larsen CM, Watanabe I, Glickman GN, et al. 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.
  24. Pruett JP, Clement DJ, Carnes Jr DL. Cyclic fatigue testing of nickel-titanium endodontic instruments. J Endod 1997;23(2):77–85. DOI: 10.1016/S0099-2399(97)80250-6.
  25. Elnaghy AM, Elsaka SE, Mandorah AO. In vitro comparison of cyclic fatigue resistance of TruNatomy in single and double curvature canals compared with different nickel-titanium rotary instruments. BMC Oral Health 2020;20(1):1–8. DOI: 10.1186/s12903-020-1027-7.
  26. Shen Y, Zhou HM, Zheng YF, et al. Current challenges and concepts of the thermomechanical treatment of nickel-titanium instruments. J Endod 2013;39(2):163–172. DOI: 10.1016/j.joen.2012.11.005.
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