[Clinical accuracy of lpex apex locator for measurement of root canal length of primary molars]

Radiography is the most commonly used technique for root canal length determination; but its application in pedodontics is difficult due to problems namely the radiation hazards, superimposition of permanent teeth buds and uncooperative children. Electronic apex locator [EAL] is used for determination of root canal length. The aim of this study was to assess the accuracy of an Electronic Apex Locator [Ipex] in measuring the root canal length of primary teeth in-vivo. This clinical study was conducted on 50 root canals of primary teeth that had to be extracted. After local anesthesia induction and caries removal, access cavities were prepared and the length of root canals was measured using Ipex Electronic Apex Locator. After the extraction of teeth, the actual length of canals was measured using a #15 K file from a reference point. Data were analyzed using paired t-test and intra-class correlation coefficient. The accuracy of Ipex was 20% for accurate determination of actual root canal length, 66% for estimation within +/- 0.5mm of the apex and 80% for estimation within +/- 1mm of the apex. Paired t-test revealed a significant difference between the actual root canal length and the length displayed by Ipex [P<0.001]. A direct strong correlation existed between the length measured by Ipex and the actual root canal length [r=0.957] Ipex had a tendency to underestimate the actual root canal length. Since the working length is shorter than the actual root canal length, Ipex may be used for endodontic treatment of primary teeth