Clinical evaluation of the accuracy of conventional radiography and apex locators in primary teeth

The purpose of this study was to clinically evaluate the accuracy of conventional radiography and 2 apex locators (Root ZX and ProPex) in determining the working length of root canals in primary teeth and to compare the results with scanning electron microscopy (SEM). Methods: A general medical and oral history was obtained from 1,600 children and 50 children were selected. The working lengths of the primary teeth root canals were determined with conventional radiography and 2 apex locators (Root ZX and ProPex). These results were compared with the ideal standard using SEM. To determine the difference among means of the different methods, the Wilcoxon test was applied. To determine the accuracy of the methods with the ideal standard (SEM), the Lin interclass correlation coefficient (ICC) was used. Results: Sixty-one canals were evaluated and there were no significant difference in the 3 techniques in accuracy of determination of the working length of the canals. The most accurate method of determining the working length of the root canals in primary teeth was the Root ZX (ICC=0.72), followed by the ProPex (ICC=0.70), and the least accurate was conventional radiography (ICC=0.67). Conclusion: The apex locators were more accurate than conventional radiography in determining the working length. (Pediatr Dent 2011;33:) Received June 25, 2009 | Last Revision September 21, 2009 | Accepted September 22, 2009