J Korean Acad Conserv Dent.  2006 Mar;31(2):113-118. 10.5395/JKACD.2006.31.2.113.

The instrument-centering ability of four Nickel-Titanium instruments in simulated curved root canals

• Ku JH
• Chang HS
• Chang SW
• Cho HH
• Bae JM
• Min KS

• KMID: 1986856
• DOI: http://doi.org/10.5395/JKACD.2006.31.2.113

Abstract

The aim of this study was to evaluate the ability of newly marketed NRT instruments to maintain the original root canal configuration and curvature during preparation in comparison with the three existing instruments in simulated root canals. Simulated canals in resin blocks were prepared with ProFile, K3, ProTaper, and NRT instrument (n = 10 canals in each case). Pre- and post-operative images were recorded, and assessment of canal shape was completed with a computer image analysis program. The data were analyzed statistically using the One-way ANOVA followed by Duncan's test. The ability of instruments to remain centered in prepared canals at 1-, 2-mm levels was significantly better in ProFile groups than in other groups (p < 0.05). The change of centering ratio in NRT groups at 5-mm level was significantly greater than ProFile group and at 6- and 7-mm level than all other groups (p < 0.05). Although the NRT system was comparable to other systems in regards to its ability to maintain the canal configuration of apical portion, this system was more influenced by the mid-root curvature due to its stainless-steel files for coronal preflaring.

Keyword

Nickel-titanium; Simulated canal; Centering ratio; NRT; Stainless-steel

MeSH Terms

Dental Pulp Cavity*

Figure

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  Figure 1 A diagram indicate the points at which the canal width were measured after superimposition of pre-operative and post-operative images.

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  Figure 2 X1 represents the maximum extent of canal movement in one direction and X2 is the movement in the opposite direction. Y is the diameter of the final canal preparation.

Reference

1. Al-Omari MAO, Dummer PMH, Newcombe RG. Comparison of six files to prepare simulated root canals. Part 2. Int Endod J. 1992. 25:67–81.

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

3. Wu MK, Wesselink PR. Efficacy of three techniques in cleaning the apical portion of curved canals. Oral Surg Oral Med Oral Pathol Oral Radiol Endod. 1995. 79:492–496.

4. Zmener O, Banegas G. Comparison of three instrumentation techniques in the preparation of simulated root canals. Int Endod J. 1996. 29:315–319.

5. Schneider SW. A comparison of canal preparations in straight and curved root canals. Oral Surg Oral Med Oral Pathol. 1971. 32:271–275.

6. Calhoun G, Montgomery S. The effects of four instrumentation techniques on root canal shape. J Endod. 1988. 14:273–277.

7. Peters OA, Schonenberger K, Laib A. Effects of four Ni-Ti preparation techniques on root canal geometry assessed by micro computed tomography. Int Endod J. 2001. 34:221–230.

8. 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. 2003. 29:15–19.

9. Yoshimine Y, Ono M, Akamine A. The shaping effects of three nickel-titanium rotary instruments in simulated S-shaped canals. J Endod. 2005. 31:373–375.

10. Yun HH, Kim SK. A comparison of the shaping abilities of 4 nickel-titanium rotary instruments in simulated root canals. Oral Surg Oral Med Oral Pathol Oral Radiol Endod. 2003. 95:228–233.

11. Guelzow A, Stamm O, Martus P, Kielbassa AM. Comparative study of six rotary nickel-titanium systems and hand instrumentation for root canal preparation. Int Endod J. 2005. 743–752.

12. Iqbal MK, Firic S, Tulcan J, Karabucak B, Kim S. Comparison of apical transportation between ProFile and ProTaper NiTi rotary instruments. Int Endod J. 2004. 37:359–364.

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

14. Davis RD, Marshall JG, Baumgartner JC. Effect of early coronal flaring on working length change in curved canals using rotary nickel-titanium versus stainless steel instruments. J Endod. 2002. 28:438–442.

15. Dummer PMH, Alodeh MHA, Al-Omari MAO. A method for theconstruction of simulated canals in clear resin blocks. Int Endod J. 1991. 24:63–66.