the effect of file size on the accuracy of the raypex 5 apex locator: an in vitro study

background and aims. determining the proper length of the root canals is essential for successful endodontic treatment. the purpose of this in vitro study was to evaluate the effect of file size on the accuracy of the raypex 5 electronic apex locator for working length determination of uninstrumented canals. materials and methods. twenty maxillary central incisors with single straight canals were used. following access cavity preparation, electronic working length by means of raypex 5 apex locator and actual working length were determined. data were analyzed using anova with repeated measurements and lsd test. results. there was no significant difference between electronic and actual working lengths when a size 15 k-file was used. conclusion. under the conditions of the present study, a size 15 k-file is a more suitable size for determining working length.