[In vitro evaluation of the accuracy of two new electronic apex locators in root canal length determination]

ABSTRACT

Radiography is still the common method of measuring working length in root canal therapy. While, gag reflex, pregnancy or superimposition of anatomical structures on root canal may be considered as some of the limitations to this procedure. Therefore, application of any accessory measurement device may be useful. The aim of this investigation was to assess the ability of two apex locator systems [Ipex and Raypex5] in measuring root canal length accurately. A total of 160 extracted human teeth were used in this laboratory investigation. The teeth were divided into 3 groups of single-canal, two-canal and three-canal teeth. The access cavities were then prepared and the actual length of each canal was measured by inserting an appropriate file into the canal until the tip of the file was seen at the apical foramen. The Donnelly test medium was prepared and each tooth was placed in the medium up to the CEJ. The length of each tooth was measured again and recorded using Ipex and Raypex5 systems. The data were statistically analyzed using Liner-Regression, McNemar and t-tests. The accuracy of Raypex5 showed to be 83.1% [95% CI 77.3-89]. Likewise the accuracy of Ipex was 78.8% [95% CI 72.3-85.2]. Both measurements were with in the limits of +/- 0.5mm from apical foramen. Mc Nemar test showed no significant difference between the two groups [P=0.337]. Based on the results of this study, it can be concluded that manufacturers' data are not always reliable. However, these systems can be used as accessories in addition to radiography for accurate working length measurements