A Comparative Study of Factors Affecting Cyclic Fatigue Resistance Between Tapering and Metallurgic Improvement of NiTi Rotary Files
Main Article Content
Abstract
The purpose of this study was to evaluate factors affecting cycling fatigue resistance by comparing between different tapers and metallurgic improvement of NiTi rotary files. Total numbers of 90 files; no.25, 30, 35 of K3 files (0.02, 0.04 fixed taper), and no.25, 30, 35 of K3XF files (0.04 fixed taper), were divided into 9 groups of 10 files each. Samples were rotated in an artificial canal until fractured, and the number of cycles to failure were subsequently recorded. The surfaces of fractured instruments were analyzed by using scanning electron microscope at 200 magnification to determine the surface characteristics. The results showed that, among files with the same size, tapering of the files had more effects on the numbers of cycle to failure than metallurgic improvement did. SEM analysis revealed that the fractured surfaces of all instruments was due to cyclic fatigue. In conclusion, tapering of the files has more effects on cyclic fatigue resistance than metallurgic improvement by R-phase heat treatment of NiTi rotary files with identical geometric characteristics.
Article Details
บทความ ข้อมูล เนื้อหา รูปภาพ ฯลฯ ที่ได้รับการลงตีพิมพ์ในวิทยาสารทันตแพทยศาสตร์ มหาวิทยาลัยขอนแก่นถือเป็นลิขสิทธิ์เฉพาะของคณะทันตแพทยศาสตร์ มหาวิทยาลัยขอนแก่น หากบุคคลหรือหน่วยงานใดต้องการนำทั้งหมดหรือส่วนหนึ่งส่วนใดไปเผยแพร่ต่อหรือเพื่อกระทำการใด ๆ จะต้องได้รับอนุญาตเป็นลายลักษณ์อักษร จากคณะทันตแพทยศาสตร์ มหาวิทยาลัยขอนแก่นก่อนเท่านั้น
References
2. Peters OA, Barbakow F. Dynamic torque and apical forces of ProFile .04 rotary instruments during preparation of curved canals. Int Endod J 2002;35(4):379-89.
3. Peters OA. Current challenges and concept in the preparation of root canal systems: a review. J Endod 2004;30(8):559-67.
4. Schafer E, Schulz-Bongert U, Tulus G. Comparison of hand stainless steel and nickel titanium rotary instrumentation: a clinical study. J Endod 2004;30(6):432-5.
5. Glickman GN, Koch KA. 21st-century endodontics. J Am Dent Assoc 2000;131(6):39S-46S.
6. Sattapan B, Nervo GJ, Palamara JE, Messer HH. Defects in rotary nickel-titanium files after clinical use. J Endod 2000;26(3):161-65.
7. Ansari I, Maria R. Managing curved canals. Contemp Clin Dent 2012;3(2):237-41.
8. Cheung GS, Peng B, Bian Z, Shen Y, Darvell BW. Defects in ProTaper S1 instruments after clinical use: fractographic examination. Int Endod J 2005;38(11):802-9.
9. Haïkel Y, Serfaty R, Bateman G, Senger B, Allemann C. Dynamic and cyclic fatique of engine-driven rotary nickel-titanium endodontic instruments. J Endod 1999;25(6):434-40.
10. Gambarini G. Cyclic fatique of profile rotary instruments after prolonged clinical use. Int Endod J 2001;34(4):386-9.
11. Ha JH, Kim SK, Cohenca N, Kim HC. Effect of R-phase heat treatment on torsional resistance and cyclic fatigue fracture. J Endod 2013;39(3):389-93.
12. Perez-Higueras JJ, Arias A, de la Macorra JC. Cyclic fatigue resistance of K3, K3XF and Twisted file nickel titanium files under continuous rotation or reciprocating motion. J Endod 2013;39(1):1585-8.
13. Lopes HP, Gamgarra-Soares T, Elias CN, Siqueira JF Jr, Inojosa IF, Lopes WS, et al. Comparison of the mechanical properties of rotary instruments made of conventional nickel titanium wire, M-wire or nickel titanium alloy in R-phase. J Endod 2013;39(4):516-20.
14. Johnson E, Lloyd A, Kuttler S, Namerow K. Comparison between a novel nickel titanium alloy and 508 nitinol on the cyclic fatigue of Profile 25/.04 rotary instruments. J Endod 2008;34(11):1406-9.
15. Arias A, Perez-Higueras JJ, de la Macorra JC. Influence of clinical usage of GT and GTX files on cyclic fatigue resistance. Int Endod J 2014;47(3):257-63.
16. Elnaghy AM. Cyclic fatigue resisitance of Protaper Next nickel titanium rotary files. Int Endod J 2014;47(11);1034-9.
17. Perez-Higueras JJ, Arias A, de la Macorra JC, Peters OA. Differences in cyclic fatigue resistance between Protaper Next aqndProtaper Universal instruments at difference levels. J Endod 2014;40(9):1477-81.
18. Plotino G, Grande N, Cordaro M, Testarelli L, Gambarini G. A review of cyclic fatigue testing of nickel-titanium rotary instruments. Int Endod J 2009;35(11):1469-76.
19. 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.
20. Gambarini G, Gerosa R, De Luca M, Garala M, Restarelli L. Mechanical properties of a new and improved nickel titanium alloy for endodontic use: an evaluation of file flexibility. Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2008;105(6):798-800.