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VOLUME 19 , ISSUE 12 ( December, 2018 ) > List of Articles


Comparison of Four Electronic Apex Locators in Detecting Working Length: An Ex Vivo Study

Mehmet Yolagiden, Seyda Ersahan, Gokhan Suyun, Erturk Bilgec, Cumhur Aydin

Keywords : Apex ID, Apex Pointer+, Apical constriction, Electronic apex locator, Raypex 5, Raypex 6, Working length determination

Citation Information : Yolagiden M, Ersahan S, Suyun G, Bilgec E, Aydin C. Comparison of Four Electronic Apex Locators in Detecting Working Length: An Ex Vivo Study. J Contemp Dent Pract 2018; 19 (12):1427-1433.

DOI: 10.5005/jp-journals-10024-2444

License: CC BY-NC 4.0

Published Online: 01-05-2019

Copyright Statement:  Copyright © 2018; The Author(s).


Aim: To compare the accuracy of four different electronic apex locators (EALs) in detecting a position 0.5 mm short of the major foramen. Materials and methods: The actual working length of thirty-five extracted human teeth was determined visually as 0.5 mm short of the apical foramen. After actual working length measurements, electronic working length was measured with four different EALs (Apex Pointer+, Raypex 5, Apex ID, and Raypex 6). Measurements were repeated three times by different operators. The data were analyzed using the intraclass correlation coefficient (ICC), the repeated measure analysis of variance (rANOVA) and Bonferroni post hoc tests. The significance level was set at p. 0.05. Results: The mean differences between electronic and actual working length were.0.305 mm, 0.098 mm, 0.037, and 0.144 mm for the Apex Pointer+, the Raypex 5, the Apex ID, and the Raypex 6, respectively. Multiple paired comparisons (Bonferroni test) also showed the Apex Pointer+ is significantly different from the Raypex 5, Apex ID and Raypex 6 (p = 0.000, p = 0.001, and p = 0.001 respectively). Conclusion: All EALs showed an acceptable determination of the working length between the ranges of ± 0.5mm except for the Apex Pointer+ device, which had the lowest accuracy. Further studies may be beneficial especially to better evaluate the accuracy of the Apex Pointer+. Clinical significance: This article shows that Apex ID, which has only recently been introduced into the market, showed an acceptable determination of the working length. Its accuracy was similar to that of Raypex 5 and 6.

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  1. Glossary of endodontic terms, 7th edn. lications/03GlossaryofEndoTerms_Web(1).pdf. American Association of Endodontists, 2003.
  2. Sjögren U, Hagglund B, Sundqvist G, Wing K. Factors affecting the long-term results of endodontic treatment. J Endod. 1990 Oct;16(10):498-504.
  3. Stein TJ, Corcoran JF, Zillich RM. The influence of the major and minor foramen diameters on apical electronic probe measurements. J Endod. 1990 Nov;16(11):520-522.
  4. Green D. A stereomicroscopic study of 700 root apices of maxillary and mandibular posterior teeth. Oral Surg Oral Med Oral Pathol Oral Radiol Endod. 1960 Jun;13:728-733.
  5. ElAyouti A, Weiger R, Löst C. Frequency of overinstrumentation with an acceptable radiographic working length. J Endod. 2001 Jan;27(1):49-52.
  6. Palmer MJ, Weine FS, Healey HJ. Position of the apical foramen in relation to endodontic therapy. J Can Dent Assoc (Tor). 1971 Aug;37(8):305-308.
  7. Kim E, Marmo M, Lee CY, Oh NS, Kim IK. An in vivo comparison of working length determination by only root-ZX apex locator versus combining root-ZX apex locator with radiographs using a new impression technique. Oral Surg Oral Med Oral Pathol Oral Radiol Endod. 2008 Apr;105(4): 79-83.
  8. Smadi L. Comparison between two methods of working length determination and its effect on radiographic extent of root canal filling: a clinical study. BMC Oral Health. 2006 Feb;6:4.
  9. Hoer D, Attin T. The accuracy of electronic working length determination. Int Endod J. 2004 Feb;37(2):125-131.
  10. Altenburger MJ, Cenik Y, Schirrmeister JF, Wrbas KT, Hellwig E. Combination of apex locator and endodontic motor for continuous length control during root canal treatment. Int Endod J. 2009 Apr;42(4):368-374.
  11. Suzuki K. Experimental study on iontophoresis. J Jap Stomatol. 1942;16:411.
  12. Sunada I. New method for measuring the length of the root canal. J Dent Res. 1962;41:375-387.
  13. Briseno-Marroquýn B, Frajlich S, Goldberg F, Willershausen B. Influence of instrument size on the accuracy of different apex locators: an in vivo study. J Endod. 2008 Jun;34(6): 698-702.
  14. Marigo L, Gervasi GL, Somma F, Squeo G, Castagnola R. Comparison of two electronic apex locators on human cadavers. Clin Oral Investig. 2016 Sep;20(7):1547-1550.
  15. Lucena C, Lopez JM, Martin JA, Robles V, Gonzalez-Rodriguez MP. Accuracy of working length measurement: electronic apex locator versus cone beam computed tomography. Int Endod J. 2014 Mar;47(3);246-256.
  16. De Vasconcelos BC, Verissimo Chavez RD, Vivacqua-Gomes N, Candeiro GT, Bernardes RA, Vivan RR, et al. Ex vivo evaluation of the accuracy of electronic foramen locators in root canals with an obstructed foramen. J Endod. 2015 Sep;41(9):1551-1554.
  17. Piasecki L, Carneiro E, da Silva Neto UX, Westphalen VP, Brandao CG, Gambarini G, et al. The use of micro computed tomography to determine the accuracy of 2 electronic apex locators and anatomic variations affecting their precision. J Endod. 2016 Aug;42(8):1263-1267.
  18. Nekoofar M, Ghandi M, Hayes S, Dummer P. The fundamental operating principles of electronic root canal length measurement devices. Int Endod J. 2006 Aug;39(8):595-609.
  19. Chen E, Kaing S, Mohan H, Ting SY, Wu J, Parashos P. An ex vivo comparison of electronic apex locator teaching models. J Endod. 2011 Aug;37(8):1147-1151.
  20. Dummer PM, McGinn JH, Rees DG. The position and topography of the apical canal constriction and apical foramen. Int Endod J. 1984 Oct;17(4):192-198.
  21. Lee SJ, Nam KC, Kim YJ, Kim DW. Clinical accuracy of a new apex locator with an automatic compensation circuit. J Endod. 2002 Oct;28(10):706-709.
  22. Martínez-Lozano MA, Forner-Navarro L, Sánchez-Cortés JL, Llena-Puy C. Methodological considerations in the determination of working length. Int Endod J. 2001 Jul;34(5): 371-376.
  23. Duran-Sindreu F, Stöber EK, Mercadé M, Vera J, García M, Bueno R, et al. Comparison of in vivo and In vitro readings when testing the accuracy of the Root ZX Apex Locator. J Endod. 2012 Feb;38(2):236-239.
  24. Meares WA, Steiman HR. The influence of sodium hypochlorite irrigation on the accuracy of the Root ZX electronic apex locator. J Endod. 2002 Aug;28(8):595-598.
  25. Wrbas KT, Ziegler AA, Altenburger MJ, Schirrmeister JF. In vivo comparison of working length determination with two electronic apex locators. Int Endod J. 2007 Feb;40(2): 133-138.
  26. Baldi JV, Victorino FR, Bernardes RA, de Moraes IG, Bramante CM, Garcia RB, et al. Influence of embedding media on the assessment of electronic apex locators. J Endod. 2007 Apr;33(4):476-479.
  27. Mull JP, Manjunath V, Manjunath M. Comparison of accuracy of two electronic apex locators in the presence of various irrigants: an in vitro study. J Conserv Dent. 2012 Apr;15(2):178-182.
  28. Venturi M, Breschi L. A comparison between two electronic apex locators: an ex vivo investigation. Int Endod J. 2007 May;40(5):362-373.
  29. Fouad AF, Krell KV, McKendry DJ, Koorbusch GF, Olson RA. Clinical evaluation of five electronic root canal length measuring instruments. J Endod. 1990 Sep;16(9): 446-449.
  30. Ricard O, Roux D, Bourdeau L, Woda A. Clinical evaluation of the accuracy of the Evident RCM Mark II apex locator. J Endod. 1991 Nov;17(11):567-569.
  31. Ding J, Gutmann JL, Fan B, Lu Y, Chen H. Investigation of apex locators and related morphological factors. J Endod. 2010 Aug;36(8):1399-1403.
  32. Cimilli H, Aydemir S, Kartal N, Chandler N. Comparing the accuracy of four electronic apex locators for determining the minor diameter: An ex vivo study. J Dent Sci. 2013;8: 27-30.
  33. Swapna DV, Krishna A, Patil AC, Rashmi K, Pai VS, Ranjini MA. Comparison of third generation versus fourth generation electronic apex locators in detecting apical constriction: An in vivo study. J Conserv Dent. 2015 Jul-Aug;18(4):288-291.
  34. Aydin U, Karataslioglu E, Aksoy F, Yildirim C. In vitro evaluation of Root ZX and Raypex 6 in teeth with different apical diameters. J Conserv Dent. 2015 Jan-Feb;18(1):66-69.
  35. APEX ID. Owner's manual. Glendora: Sybron Endo; 2014.
  36. ElAyouti A, Kimionis I, Chu AL, Lost C. Determining the apical terminus of root-end resected teeth using three modern apex locators: a comparative ex vivo study. Int Endod J. 2005 Nov;38(11):827-833.
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