Comparative study on morphology of cross-section and cyclic fatigue test with different rotary NiTi files and handling methods

Article information

Restor Dent Endod. 2006;31(2):96-102

Publication date (electronic) : 2006 March 31

doi : https://doi.org/10.5395/JKACD.2006.31.2.096

Jae-Gwan Kim ¹, Kee-Yeon Kum ², Eui-Seong Kim ¹

¹Department of Conservative Dentistry, Yonsei University, Korea.

²Department of Conservative Dentistry, Dental Research Institute, Seoul National University, Korea.

Corresponding Author: Eui-Seong Kim. Department of conservative Dentistry, College of Dentistry, Yonsei University, 134 Shinchon-Dong, Seodaemoon Gu, Seoul, Korea, 120-752. Tel: 82-2-361-8711, Fax: 82-2-313-7575, andyendo@yumc.yonsei.ac.kr

Received 2005 October 13; Revised 2005 December 28; Accepted 2006 January 26.

Abstract

There are various factors affecting the fracture of NiTi rotary files. This study was performed to evaluate the effect of cross sectional area, pecking motion and pecking distance on the cyclic fatigue fracture of different NiTi files. Five different NiTi files-Profile®(Maillefer, Ballaigue, Switzerland), ProTaper™ (Maillefer, Ballaigue, Switzerland), K3® (SybronEndo, Orange, CA), Hero 642® (Micro-mega, Besancon, France), Hero Shaper®(Micro-mega, Besancon, France)-were used. Each file was embedded in temporary resin, sectioned horizontally and observed with scanning electron microscope. The ratio of cross-sectional area to the circumscribed circle was calculated. Special device was fabricated to simulate the cyclic fatigue fracture of NiTi file in the curved canal,. On this device, NiTi files were rotated (300rpm) with different pecking distances (3 mm or 6 mm) and with different motions (static motion or dynamic pecking motion). Time until fracture occurs was measured. The results demonstrated that cross-sectional area didn't have any effect on the time of file fracture. Among the files, Profile® took the longest time to be fractured. Between the pecking motions, dynamic motion took the longer time to be fractured than static motion. There was no significant difference between the pecking distances with dynamic motion, however with static motion, the longer time was taken at 3mm distance. In this study, we could suggest that dynamic pecking motion would lengthen the time for NiTi file to be fractured from cyclic fatigue.

Keywords: Fatigue fracture; Cross-sectional area; Pecking motion; Pecking distance

References

1. Serene TP, Adams JD, Saxena A. Nickel-Titanium instruments: applications in Endodontics 1995. St.Louis: Ishiyaku EuroAmerica, Inc;

2. Yoneyama T, Doi H, Hamanaka H. Influence of composition and purity on tensile properties of NiTi alloy castings. Dent Mater J 1992. 11157–164.

3. Walia HM, Brantley WA, Gerstein H. An initial investigation of the bending and torsional properties of nitinol root canal files. J Endod 1988. 14346–351.

4. Stoekel D, Yu W. Superelastic NiTi wire. Wire J Int 1991. 345–50.

5. Glossen CR, Haller RH, Dove SB, del Rio CE. A comparison of root canal preparations using NiTi hand, NiTi engine driven, and K-Flex endodontic enstruments. J Endod 1995. 21146–151.

6. Cohen S, Burns RC. Pathways of the pulp 1998. 7th edth ed. St.Louis: Mosby Year Book, Inc; 255.

7. Serene TP, Adams JD, Saxena A. Nickel-Titanium instruments: applications in Endodontics 1995. St.Louis: Ishiyaku EuroAmerica, Inc; 62–63.

8. Zelada G, Varela P, Martin B, Bahilo JG, Magan F, Ahn S. The effect of rotational speed and the curvature of root canals on the breakage of rotary endodontic instruments. J Endod 2002. 28540–542.

9. Pruett JP, Clement DJ, Carnes DL. Cyclic fatigue testing of nickel-titanium endodontic instruments. J Endod 1997. 2377–85.

10. Turpin YL, Chagneau F, Vulcain JM. Impact of two theoretical cross-sections on torsional and bending stresses of nickel-titanium root canal instrument models. J Endod 2000. 26414–417.

11. Li UM, Lee BS, Shih CT, Lan WH, Lin CP. Cyclic fatigue of endodontic nickel titanium rotary instruments: Static and dynamic tests. J Endod 2002. 28448–451.

12. Shin YM, Kim ES, Kim KM, Kum KY. Effect Of surface defects and cross-sectional configuration on the fatigue fracture of NiTi rotary files under cyclic loading. J Korean Acad Conserv Dent 2004. 29267–272.

13. Park WK, Lee HJ, Hur B. Sahping ability of NiTi rotary files. J Korean Acad Conserv Dent 2004. 2944–50.

14. Lee JH, Kim MJ, Seok CI, Lee WC, Baek SH. Evaluation of canal preparation with NiTi rotary files by micro computed tomography. J Korean Acad Conserv Dent 2004. 29378–385.

15. Haïkel Y, Sefaty R, Bateman G, Senger B, Allemann C. Dynamic and cyclic fatigue test of engine-driven rotary nicketl titanium endodontic instruments. J Endod 1999. 25434–440.

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