Restorative Dentistry and Endodontics

  • 제34권5호
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  • Pages.424-429
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  • 2009
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  • 2234-7658(pISSN)
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  • 2234-7666(eISSN)
대한치과보존학회 (The Korean Academy of Conservative Dentistry)
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반복 굽힘 스트레스 하에서 전동식 니켈-티타늄 파일의 단면적의 크기가 피로파절에 미치는 영향 : 파절역학 분석

EFFECT OF CROSS-SECTIONAL AREA OF 6 NICKEL-TITANIUM ROTARY INSTRUMENTS ON THE FATIGUE FRACTURE UNDER CYCLIC FLEXURAL STRESS: A FRACTOGRAPHIC ANALYSIS

  • 황수연 (서울대학교 치의학 전문대학원 치과보존학교실) ;
  • 오소람 (서울대학교 치의학 전문대학원 치과보존학교실) ;
  • 이윤 (서울대학교 치의학 전문대학원 치과보존학교실) ;
  • 임상민 (서울대학교 치의학 전문대학원 치과보존학교실) ;
  • 금기연 (서울대학교 치의학 전문대학원 치과보존학교실)
  • Hwang, Soo-Youn (Department of Conservative Dentistry, School of Dentistry, Seoul National University) ;
  • Oh, So-Ram (Department of Conservative Dentistry, School of Dentistry, Seoul National University) ;
  • Lee, Yoon (Department of Conservative Dentistry, School of Dentistry, Seoul National University) ;
  • Lim, Sang-Min (Department of Conservative Dentistry, School of Dentistry, Seoul National University) ;
  • Kum, Kee-Yeon (Department of Conservative Dentistry, School of Dentistry, Seoul National University)
  • 발행 : 2009.09.30
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초록

본 연구의 목적은 니켈 티타늄 전동파일의 피로 파절에 파일의 단면 형태가 미치는 영향을 평가하고자 하였다. 6 종의 ProFile (Dentsply), Mtwo (VDW), K3 (SybronEndo), Heroshaper (MicroMega), NRT (Mani), Alpha system (KOMET) 니켈-티타늄 전동 파일(ISO 30 size/.04 taper)을 각 10개씩 실험군으로 배정하고 실험을 진행하였다. 니켈 티타늄 전동파일에 반복적인 장력과 압축력을 재현시킬 수 있는 피로파절 실험기(Denbotix)와 연결된 토크 조절 전동모터(Aseptico)에 각 군의 파일을 연결하여 300rpm 속도로 만곡도가 60도이고 5mm의 반경을 가진 인공 금속 근관 내를 6 mm pecking depth로 작동시켰다. 각 파일의 파절시간을 측정하고 통계 분석하여 유의성을 분석하였으며, 각 군의 파절된 모든 파일의 파절면을 주사전자현미경을 이용한 fractographic analysis를 통해 파절 역학을 규명하였다. 또한 각 군에서 3개의 사용하지 않은 새 파일을 clear resin에 매몰하고tip에서부터 3mm 지점을 횡절단하여 Image-Pro Plus (Imagej 1.34n, NIH) 소프트웨어로 절단면의 단면적을 측정하고 단면적의 크기와 피로 파절과의 상관성도 평가하였다. 실험 결과 NRT와 ProFile이 다른 실험군에 비해서 유의성 있게 높은 피로 파절 저항성을 보였다(P < .05). 또한 파일의 단면적은 피로파절 저항성과 통계학적인 유의성은 보이지 않았다. Fractographic analysis 결과 모든 시편에서 파절면은 ductile fracture와 brittle fracture가 혼재된 양상으로 나타났다. 결론적으로 니켈 티타늄 전동 파일의 단면적의 크기는 피로파절 저항과는 상관성이 적었다.

This study aimed to assess the influence of different cross-sectional area on the cyclic fatigue fracture of Ni-Ti rotary files using a fatigue tester incorporating cyclical axial movement. Six brands of Ni-Ti rotary files (ISO 30 size with. 04 taper) of 10 each were tested: Alpha system (KOMET), HeroShaper (MicroMega), K3 (SybronEndo), Mtwo (VDW), NRT (Mani), and ProFile (Dentsply). A fatigue-tester (Denbotix) was designed to allow cyclic tension and compressive stress on the tip of the instrument. Each file was mounted on a torque controlled motor (Aseptico) using a 1:20 reduction contra-angle and was rotated at 300 rpm with a continuous, 6 mm axial oscillating motion inside an artificial steel canal. The canal had a $60^{\circ}$ angle and a 5 mm radius of curvature. Instrument fracture was visually detected and the time until fracture was recorded by a digital stop watch. The data were analyzed statistically. Fractographic analysis of all fractured surfaces was performed to determine the fracture modes using a scanning electron microscope. Cross-sectional area at 3 mm from the tip of 3 unused Ni-Ti instruments for each group was calculated using Image-Pro Plus (Imagej 1.34n, NIH). Results showed that NRT and ProFile had significantly longer time to fracture compared to the other groups (p < .05). The cross-sectional area was not significantly associated with fatigue resistance. Fractographycally, all fractured surfaces demonstrated a combination of ductile and brittle fracture. In conclusion, there was no significant relationship between fatigue resistance and the cross-sectional area of Ni-Ti instruments under experimental conditions.

키워드

참고문헌

  1. Esposito PT, Cunningham CJ. A comparison of canal preparation with nickel-titanium and stainless steel instruments. J Endod 21:173-176, 1995 https://doi.org/10.1016/S0099-2399(06)80560-1
  2. Peters OA. Current challenges and concepts in the preparation of root canal systems: a review. J Endod 30:559-567, 2004 https://doi.org/10.1097/01.DON.0000129039.59003.9D
  3. Kosa DA, Marshall G, Baumgartner JC. An analysis of canal centering using mechanical instrumentation techniques. J Endod 25:441-5, 1999 https://doi.org/10.1016/S0099-2399(99)80275-1
  4. Bahia MGA, Melo MCC, Buono VTL. Influence of simulated clinical use on the torsional behavior of nickeltitanium rotary endodontic instruments. Oral Surg Oral Med Oral Pathol Oral Radiol Endod 101: 675- 680, 2006 https://doi.org/10.1016/j.tripleo.2005.04.019
  5. Pruett JP, Clement DJ, Carnes DL. Cyclic fatigue testing of nickel-titanium endodontic instruments. J Endod 23:77-85, 1997 https://doi.org/10.1016/S0099-2399(97)80250-6
  6. Sattapan B, Nervo GJ, Palamara JEA, Messer HH. Defects in rotary nickel-titanium files after clinical use. J Endod 26: 161-5, 2000 https://doi.org/10.1097/00004770-200003000-00008
  7. 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 26: 414-7, 2000 https://doi.org/10.1097/00004770-200007000-00009
  8. Xu X, Zheng Y, Eng D. Comparative study of torsional and bending properties for six models of nickel-titanium root canal instruments with different cross-sections. J Endod 32:372-375, 2006 https://doi.org/10.1016/j.joen.2005.08.012
  9. Berutti E, Chiandussi G, Gaviglio I, Ibba A. Comparative analysis of torsional and bending stresses in two mathematical models of nickel-titanium rotary instruments: ProTaper versus ProFile. J Endod 29: 15-9, 2003 https://doi.org/10.1097/00004770-200301000-00005
  10. Cheung GS, Darvell BW. Low-cycle fatigue of Ni-Tirotary instruments of various cross-sectional shapes. Int Endod J 40: 626-632. 2007 https://doi.org/10.1111/j.1365-2591.2007.01257.x
  11. Shin YM, Kim ES, Kim KM, Kum KY. Effect of surface defects and cross-sectional configurations on the fatigue fracture of Ni-Ti rotary files in a dynamic model. J Kor Cons Dent 29:267-272, 2004 https://doi.org/10.5395/JKACD.2004.29.3.267
  12. Kim JK, Kum KY, Kim ES. Comparative study on morphology of cross-section and cyclic fatigue test with different rotary Ni-Ti files and handling methods. J Kor Cons Dent 31:96-102, 2006
  13. Haikel Y, Serfaty R, Bateman G, Senger B, Alleman C. Dynamic and cyclic fatigue of engine-driven rotary nickel-titanium endodontic instruments. J Endod 25: 434-440, 1999 https://doi.org/10.1016/S0099-2399(99)80274-X
  14. Li UM, Lee BS, Shih CT, Lan WH, Lin CP. Cyclic fatigue of endodontic nickel titanium rotary instruments: Static and dynamic tests. J Endod 28:448-51, 2002 https://doi.org/10.1097/00004770-200206000-00007
  15. Dederich DN, Zakariasen KL. The effects of cyclical axial motion on rotary endodontic instrument fatigue. Oral Surg Oral Med Oral Pathol 61:192-6, 1986 https://doi.org/10.1016/0030-4220(86)90186-6
  16. Dieter GE. Mechanical metallurgy, 3rd ed. New York: McGraw-Hill, pp.119, 138,185-8, 382-7, 394, 1986
  17. Schafer E, Dzepina A, Danesh G. Bending properties of rotary nickel-titanium instruments. Oral Surg Oral Med Oral Pathol Oral Radiol Endod 96:757-63, 2003 https://doi.org/10.1016/S1079-2104(03)00358-5
  18. Ruddle CL. Nickel-titanium rotary systems: review of existing instruments and geometries. Dent Today 19:86-95, 2000
  19. Yao JH, Schwartz SA, Beeson TJ. Cyclic fatigue of three types of rotary nickel-titanium files in a dynamic model. J Endod 32:55-65, 2006 https://doi.org/10.1016/j.joen.2005.10.013
  20. Tripi TR, Bonaccorso A, Condorelli GG. Cyclic fatigue of different nickel-titanium endodontic rotary instruments. Oral Surg Oral Med Oral Pathol Oral radiol Endod 102:e106-e114, 2006 https://doi.org/10.1016/j.tripleo.2005.12.012
  21. Hayashi Y, Yoneyama T, Yahata Y, Suda K. Phase transformation behavior and bending properties of hybrid nickel-titanium rotary endodontic instruments. Int Endod J 40; 247-253, 2007 https://doi.org/10.1111/j.1365-2591.2007.01203.x
  22. Ku JH, Chang HS, Jang SW, Min KS. The instrumentcentering ability of four nickel-titanium instruments in simulated curved root canals. J Kor Cons Dent 31:113- 8, 2006. https://doi.org/10.5395/JKACD.2006.31.2.113