ABSTRACT
Working length determination is a fundamental step in the endodontic treatment of primary and permanent teeth. Radiography is most commonly used for this purpose. However, it requires patient cooperation and is associated with adverse effects of radiation. Apex locators can serve as an efficient alternative for this purpose. We wanted to compare the accuracy of Root ZXII and Raypex 5 electronic apex locators for working length determination in primary teeth.METHODSThis in vitro study was performed on 154 canals of 58 extracted primary teeth. Access cavity was prepared, and a K-file was introduced into the canal until its tip was visible at the apex under a microscope. 0.5 mm was subtracted from this length to determine the actual working length. The canal length was then measured again using Root ZXII and Raypex 5 apex locators. The obtained values were compared with the actual value. Data was analysed using SPSS version 21 via paired t-test with intraclass correlation coefficient (ICC) at P<0.05 level of significance.RESULTSThe mean difference in values measured by Root ZXII and Raypex 5 and the actual working length was 0.77 ± 0.65 mm and 0.62 ± 0.58 mm, respectively. No significant difference existed in the accuracy of the two apex locators for determination of actual working length (P=0.54). The actual working length had a strong correlation with the values measured by Root ZXII (ICC=0.97) and Raypex 5 (ICC=0.95).CONCLUSIONSBoth apex locators have acceptable accuracy as an alternative to radiography for working length determination in primary teeth.