Clinical Evaluation of the Accuracy of Raypex5 Electronic Apex Locator on Root Canal Length Determination in Primary Teeth

Radiographic usage for determination of working length is difficult in children, because of hazardous irradiation, superimposition of the permanent tooth germ and primary tooth root, mouth opening limitation, lack of cooperation, and radiographic misinterpretation of primary teeth. The purpose of this clinical study was to evaluate the accuracy of the Raypex5 apex locator for root canal length determination in primary teeth. This experimental study used 23 primary second molar teeth that were scheduled for extraction. Following access cavity preparation, the working length was determined with a Raypex5 electronic apex locator. The teeth were extracted and real lengths of root canals were measured with insertion of a K-type file into the each canal until it emerged at the apical foramen. This length, minus 0.5 mm, was recorded as the real root canal length. The data were statistically analyzed using a One Sample t-test. The accuracy of the Raypex5 electronic apex locator in determining working length within 0.5 mm of the real length was 81.2% and 100% within 1mm of the real length. This study concluded that the Raypex5 apex locator is a useful tool for measuring root canal lengths in primary teeth.