RESUMO
Purpose: The aim of this ex vivo study was to compare the accuracy of radiographic and electronic root canal length determination methods, compared with actual root canal length obtained with stereomicroscope. Materials and Methods: Thirty extracted single-rooted permanent teeth were used for this study. After access preparation, actual length (AL) of the root canal were determined for each tooth by inserting a #15 file until the tip of the file was visible at the apical foramen under a stereomicroscope. The radiographic working length determination was determined with a digital radiographic system and for the electronic measurement all teeth were embedded in an alginate model to test apex locator in-vitro. Data was analyzed using the descriptive statistic and intraclass correlation coefficient. Results: No significant difference was found between the radiographic and electronic root canal working length determination (P>0.05). The percentage of electronic measurements within ±0.5 mm to the apical constriction was 93.34% and 90% for radiographic methods within ±0.5 mm of all cases compared with AL. Conclusions: The present ex vivo study showed that electronic root canal working length determination is not superior to radiographic methods. Both methods provided a good performance in determining the root canal working length.