Accuracy of electronic apex locators

Devices Accuracy of electronic apex locators Background.—A critical step in endodontic treatment is the determination of the working length, which can be challenging in some clinical situations. Endometric devices have been developed to determine working length in vivo. The accuracy of these devices was investigated. Methods.—Four electronic apex locators were compared for their ability to determine root canal length. The devices included Root ZX, Endy, Justy II, and Endox. The root canal measurements were obtained on 40 singlerooted and multirooted teeth before the teeth were extracted. Actual root canal length was then measured by sectioning the apical third longitudinally, positioning the root canal instrument, and examining the apex microscopically. Results.—Actual root canal length was measurable in all 40 teeth. The most accurate results were achieved with the Justy II. Compared to actual length, the Root ZX and Justy II obtained exact measurements in 45% of cases, the Endox in 20%, and the Endy in 18%. The Justy II device was within ±0.5 mm in 80% of cases, the Root ZX in 78%, the Endy in 67%, and the Endox in 31%. Significant differences were noted between the accuracy of the Root ZX and Endy devices and between the Justy II and Endy devices, but the accuracies of the Justy II and Root ZX devices did not differ significantly. Factors that influenced accuracy for some of the devices included vital versus

nonvital tooth status, whether the tooth was single- or multirooted, and humidity. Discussion.—The Justy II device demonstrated the most accurate results in measuring root canal length. However, overall these electronic apex locators provided a reliable way to determine endodontic working length.

Clinical Significance.—The use of apex locators can reduce the time involved in endodontic procedures, reducing patient stress and increasing operator efficiency. This report testifies to the accuracy of these devices.

Haffner C, Folwaczny M, Galler K, et al: Accuracy of electronic apex locators in comparison to actual length—An in vivo study. J Dent 33:619-625, 2005 Reprints available from C Haffner, Dept of Restorative Dentistry, Ludwig-Maximilians Univ, Goethestrasse 70, D-80336 Munich, Germany; fax: +49 89 51607631; e-mail: [email protected]

Endodontics Fractured instruments’ effect on outcome Background.—The clinical significance of a retained fractured endodontic instrument on the outcome of endodontic treatment has been variously reported as minimal to troublesome. No clinical outcome study has addressed the impact of fractured rotary nickel-titanium (NiTi) instru-

ments on endodontic treatment and retreatment. The frequency of leaving fractured instruments in a root canal after treatment and the influence of fractured NiTi instruments on the outcome of nonsurgical root canal treatment and retreatment were explored.

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