J Korean Acad Conserv Dent.  2011 Jan;36(1):59-65. 10.5395/JKACD.2011.36.1.59.

Comparison of apical transportation and change of working length in K3, NRT AND PROFILE rotary instruments using transparent resin block

• Yoon MJ
• Song MJ
• Shin SJ
• Kim E

• KMID: 1446084
• DOI: http://doi.org/10.5395/JKACD.2011.36.1.59

Abstract

OBJECTIVES
The purpose of this study is to compare the apical transportation and working length change in curved root canals created in resin blocks, using 3 geometrically different types of Ni-Ti files, K3, NRT, and Profile.
MATERIALS AND METHODS
The curvature of 30 resin blocks was measured by Schneider technique and each groups of Ni-Ti files were allocated with 10 resin blocks at random. The canals were shaped with Ni-Ti files by Crown-down technique. It was analyzed by Double radiograph superimposition method (Backman CA 1992), and for the accuracy and consistency, specially designed jig, digital X-ray, and CAD/CAM software for measurement of apical transportation were used. The amount of apical transportation was measured at 0, 1, 3, 5 mm from 'apical foramen - 0.5 mm' area, and the alteration of the working length before and after canal shaping was also measured. For statistics, Kruskal-Wallis One Way Analysis was used.
RESULTS
There was no significant difference between the groups in the amount of working length change and apical transportation at 0, 1, and 3 mm area (p = 0.027), however, the amount of apical transportation at 5 mm area showed significant difference between K3 and Profile system (p = 0.924).
CONCLUSIONS
As a result of this study, the 3 geometrically different Ni-Ti files showed no significant difference in apical transportation and working length change and maintained the original root canal shape.

Keyword

Apical transportation; K3; NRT; PROFILE; Working length changes

MeSH Terms

Dental Pulp Cavity
Nickel
Titanium
Transportation
Nickel
Titanium

Figure

• 

  Figure 1 Photograph of a jig that maintains a constant distance between a X-ray tube and a resin block.

• 

  Figure 2 Photograph of a resin block and a digital sensor. (a) Holding part of digital radiographic sensor. (b) Cartesian system. (c) Table for constant position of resin block.

• 

  Figure 3 (a) Initial X-ray. (b) X-ray after canal enlargement. (c) Image of the x-ray after canal enlargement processed by Adobe photoshop.

• 

  Figure 4 (a) Image of central axis. (b) Measurement of apical transportation using AuotCAD 2000.

Reference

1. Schilder H. Cleaning and shaping the root canal. Dent Clin North Am. 1974. 18(2):269–296.

2. al-Omari MA, Dummer PM, Newcombe RG, Doller R. Comparison of six files to prepare simulated root canals. 2. Int Endod J. 1992. 25(2):67–81.

3. Schafer E, Tepel J, Hoppe W. Properties of endodontic hand instruments used in rotary motion. Part 2. Instrumentation of curved canals. J Endod. 1995. 21(10):493–497.

4. Roane JB, Sabala CL, Duncanson MG Jr. The "balanced force" concept for instrumentation of curved canals. J Endod. 1985. 11(5):203–211.

5. Abou-Rass M, Frank AL, Glick DH. The anticurvature filing method to prepare the curved root canal. J Am Dent Assoc. 1980. 101(5):792–794.

6. Caldwell JL. Change in working length following instrumentation of molar canals. Oral Surg Oral Med Oral Pathol. 1976. 41(1):114–118.

7. Civjan S, Huget EF, DeSimon LB. Potential applications of certain nickel-titanium (nitinol) alloys. J Dent Res. 1975. 54(1):89–96.

8. Walia HM, Brantley WA, Gerstein H. An initial investigation of the bending and torsional properties of Nitinol root canal files. J Endod. 1988. 14(7):346–351.

9. Gambill JM, Alder M, del Rio CE. Comparison of nickel-titanium and stainless steel hand-file instrumentation using computed tomography. J Endod. 1996. 22(7):369–375.

10. Glossen CR, Haller RH, Dove SB, del Rio CE. A comparison of root canal preparations using Ni-Ti hand, Ni-Ti engine-driven, and K-Flex endodontic instruments. J Endod. 1995. 21(3):146–151.

11. Elliott LM, Curtis RV, Pitt Ford TR. Cutting pattern of nickel-titanium files using two preparation techniques. Endod Dent Traumatol. 1998. 14(1):10–15.

12. Bergmans L, Van Cleynenbreugel J, Wevers M, Lambrechts P. Mechanical root canal preparation with NiTi rotary instruments: rationale, performance and safety. Status report for the American Journal of Dentistry. Am J Dent. 2001. 14(5):324–333.

13. Bryant ST, Thompson SA, al-Omari MA, Dummer PM. Shaping ability of Profile rotary nickel-titanium instruments with ISO sized tips in simulated root canals: Part 1. Int Endod J. 1998. 31(4):275–281.

14. Bramante CM, Berbert A, Borges RP. A methodology for evaluation of root canal instrumentation. J Endod. 1987. 13(5):243–245.

15. Garip Y, Gunday M. The use of computed tomography when comparing nickel-titanium and stainless steel files during preparation of simulated curved canals. Int Endod J. 2001. 34(6):452–457.

16. Backman CA, Oswald RJ, Pitts DL. A radiographic comparison of two root canal instrumentation techniques. J Endod. 1992. 18(1):19–24.

17. Glickman GN, Koch KA. 21st-century endodontics. J Am Dent Assoc. 2000. 131:Suppl. 39S–46S.

18. Pruett JP, Clement DJ, Carnes DL Jr. Cyclic fatigue testing of nickel-titanium endodontic instruments. J Endod. 1997. 23(2):77–85.

19. Bonetti Filho I, Miranda Esberard R, de Toledo Leonardo R, del Rio CE. Microscopic evaluation of three endodontic files pre- and postinstrumentation. J Endod. 1998. 24(7):461–464.

20. Weine FS, Kelly RF, Lio PJ. The effect of preparation procedures on original canal shape and on apical foramen shape. J Endod. 1975. 1(8):255–262.

21. Lim KC, Webber J. The validity of simulated root canals for the investigation of the prepared root canal shape. Int Endod J. 1985. 18(4):240–246.

22. Dummer PM, Alodeh MH, al-Omari MA. A method for the construction of simulated root canals in clear resin blocks. Int Endod J. 1991. 24(2):63–66.

23. Cha YB, Jung IY, Lee SJ, et al. Shaping ability of three ProFile rotary instrumentation techniques in simulated resin root canals. J Endod. 2000. 26(12):719–723.

24. Thompson SA, Dummer PM. Shaping ability of ProFile.04 Taper Series 29 rotary nickel-titanium instruments in simulated root canals. Part 1. Int Endod J. 1997. 30(1):1–7.

25. Schafer E, Florek H. Efficiency of rotary nickel-titanium K3 instruments compared with stainless steel hand K-Flexofile. Part 1. Shaping ability in simulated curved canals. Int Endod J. 2003. 36(3):199–207.

26. Iqbal MK, Maggiore F, Suh B, Edwards KR, Kang J, Kim S. Comparison of apical transportation in four Ni-Ti rotary instrumentation techniques. J Endod. 2003. 29(9):587–591.