Ex vivo accuracy of an apex locator using digital signal processing in primary teeth.

PURPOSE: The purpose of this study was to evaluate ex vivo the accuracy an electronic apex locator during root canal length determination in primary molars. METHODS: One calibrated examiner determined the root canal length in 15 primary molars (total=34 root canals) with different stages of root resorption. Root canal length was measured both visually with the placement of a K-file 1 mm short of the apical foramen or the apical resorption bevel, and electronically using an electronic apex locator (Digital Signal Processing). Data were analyzed statistically using the intraclass correlation (ICC) test. RESULTS: Comparing the actual and electronic root canal length measurements in the primary teeth showed a high correlation (ICC=0.95). CONCLUSIONS: The Digital Signal Processing apex locator is useful and accurate for apex foramen location during root canal length measurement in primary molars.