J Korean Acad Conserv Dent.  2010 Nov;35(6):453-460. 10.5395/JKACD.2010.35.6.453.

In vivo evaluation of accuracy and consistency of two electronic apex locators

• Pi CY
• Kim E
• Jung IY
• Lee SJ

• KMID: 2176467
• DOI: http://doi.org/10.5395/JKACD.2010.35.6.453

Abstract

OBJECTIVES
To evaluate the accuracy and consistency of two different apex locators at both the Apex and 0.5 marks.
MATERIALS AND METHODS
Twenty-six root canals was scheduled for extraction for periodontal or prosthodontic reasons. Thirteen canals were measured using Root ZX and the rest by i-ROOT. The root canal length was measured both the at 0.5 mark and the Apex mark. The file was then fixed to the tooth, and the distance from the file tip to the major foramen of each canal was measured after removing the root dentin under the microscope so that the major foramen and the file tip were seen.
RESULTS
1. When the Apex mark was used, 100% of both the Root ZX and i-ROOT groups were within 0.5 mm of the major foramen. 2. When 0.5 mark was used, 100% of the Root ZX group and 77% of the i-ROOT group were within 0.5 mm of the major foramen. 3. In terms of standard deviation and quartile value, the Apex mark was more consistent than 0.5 mark in the Root ZX group, and 0.5 mark was more consistent in the i-ROOT group, but there was no statistically significant difference when compared with t-test. 4. The root canal length difference between the Apex mark and 0.5 mark was 0.22 mm and 0.46 mm in the Root ZX and i-ROOT groups, respectively.
CONCLUSIONS
In this study, the Apex mark was the more consistent mark. Therefore, it is recommended to subtract 0.5 mm, which is the average length between the apex and apical constriction, from the root canal length at the Apex mark to obtain the working length clinically.

Keyword

Accuracy; Consistency; Electronic apex locator; Microscope

MeSH Terms

Constriction
Dental Pulp Cavity
Dentin
Electronics
Electrons
Prosthodontics
Tooth

Figure

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  Figure 1 Root ZX

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  Figure 2 i-ROOT

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  Figure 3 Length measurements with digital caliper.

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  Figure 4 Distance between file tip and major foramen under I-solution program (Microscope image).

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  Figure 5 Box plots: Quartile value of file tip and major foramen distance at 0.5 mark and the Apex mark.

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