Materials & Methods: A total of 30 freshly extracted mandibular firs molars were included in the present study. At approximately at cemeto-enamel junction, all the specimens were sectioned with the help of a diamond disk. This was followed by grouping of all the samples broadly into three study groups as follows: Group A: Specimens with mild canal curvature (Less than 20), Group B: Specimens with moderate canal curvature (In between 20 and 36), and Group C: Specimens with severe canal curvature (More than 36). Actual root canal length was determined through a number 10 file. This was named as actual working length (AL). Working length measured by apex locator was termed as Electronic Working Length (EL). All the results were then recorded in Microsoft excel sheet and were analysed by SPSS software.

Results: Mean difference between AL and EL was 0.139 for group A, 0.273 for group B and 0.265 for group C. While comparing statistically, significant results were obtained while comparing in between group A and group B and between Group B and group C respectively. However; while comparing between group A and group C, non-significant results were obtained.

Conclusion: Electronic working length is slight significantly affected with curvature of the root canal. However; when used with higher precision, electronic apex locators can be used regularly in dental practice with higher accuracy.