Open Access, Peer-reviewed
eISSN 2234-7666
    J Korean Acad Conserv Dent. 2009 May;34(3):232-239. Korean.
    Published online May 31, 2009.
    https://doi.org/10.5395/JKACD.2009.34.3.232
    Copyright © 2009 The Korean Academy of Conservative Dentistry
    Original Article

    Effects of anticurvature filing on danger zone width in curved root canals

    Eui Seong Kim,1,2 Hyun Jung Kim,1 Deog Gyu Seo,1 and Byoung Duck Roh1,2
      • 1Department of Conservative Dentistry, College of Dentistry, Yonsei University, Korea.
      • 2Oral Science Research Center, College of Dentistry, Yonsei University, Korea.
    • Corresponding Author: Byoung-Duck Roh. Department of Conservative Dentistry, Oral Science Research Center, College of Dentistry, Yonsei University, 250 Seongsanno, Seodaemun-Gu, Seoul 120-752, Korea. Tel: 82-2-2228-3146, Fax: 82-2-313-7575, Email: operatys16@yuhs.ac
    Received April 09, 2009; Revised April 24, 2009; Accepted May 01, 2009.

    This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/3.0/) which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited.

    Abstract

    The aim of this study was to compare the effects of anticurvature filing with stainless steel k-file versus nickel-titanium ProFile in the shaping of mesial root canals of extracted mandibular molars.

    A total of 60 canals from 30 mesial roots of mandibular molar teeth were randomly assigned to three groups with n=20 each. They were prepared with different instruments and methods: The first group with stainless steel k-file and circumferential filing, the second with precurved stainless steel k-file and anticurvature filing and the third with ProFile (.06 taper) and anticurvature filing. Using a micro-computed tomography system (skyscan-1076, SKYSCAN, Antwerpen, Belgium), pre-and post-operative specimens were scanned. Subsequently, canal images were superimposed and changes in root dentin thickness were measured at distal side (danger zone) of the canal. The data was analyzed using a one-way ANOVA and the comparison of means was conducted using a post hoc multiple comparison Tukey test.

    There were significant differences in the change of root dentin thickness at the 7.5~8.5mm level between group 1 and 2, 3.5~6mm level between group 1 and 3 and 3.5~6mm level between group 2 and 3(n=20, P<0.05).

    Keywords
    anticurvature filing; stainless steel k-file; nickel-titanium ProFile

    Figures

    Figure 1
    Pre-and Post-instrumentation canal images were superimposed and changes in root thickness were measured at distal side (danger zone) of the canal using the CTAn. Blue line is distance to external root surface pre-op and red line is post-op.

    Figure 2
    Change of root dentin thickness(mm) by canal preparation at danger zone before and after. At 7.5-8.5mm, significant differences were shown between group 1 and group 2(n=20, P<0.05). At 3.5-6mm, significant differences were shown between group 1 and group 3(n=20, P<0.05). At 3.5-6mm, significant differences were shown between group 2 and group 3(n=20, P<0.05).

    Figure 3
    Comparison of group 1 and 2. The reconstructed 3-D root canal system before and after preparation is shown and superimposed cross-section images, which shows significant difference at 7.5-8.5mm level, are also shown. In group 2, more dentin was removed in the safe zone than in the danger zone at coronal 1/3 level.

    Figure 4
    Comparison of group 1 and 3. The reconstructed 3-D root canal system before and after preparation is shown and superimposed cross-section images, which shows significant difference at 3.5-6mm level, are also shown.

    Tables

    Table 1
    Change of root dentin thickness(mm) by canal preparation at danger zone (mean ± S.D.). At 7.5~8.5mm, significant differences were shown between group1 and group2 (n=20, P<0.05). At 3.5~6mm, significant differences were shown between group1 and group3, 3.5~6mm level between group 2 and 3 (n=20, P<0.05).

    (B): thickness of root canal dentin at danger zone before instrumentation.

    (A): thickness of root canal dentin at safe zone after instrumentation.

    (V): Change values of root dentin thickness by canal preparation at danger zone.

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    MeSH Terms
    Dental Pulp Cavity
    Dentin
    Molar
    Stainless Steel
    Tooth
    Metrics
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