Materials & Methods: The present study was conducted on 90 mandibular molar teeth of either gender. The degree of root canal curvature was determined by Schneider’s method. Samples were divided into three groups. Group I were with mild canal curvature (< 20°), group II were moderate canal curvature (20-36°) and group III were severe canal curvature (>36°).

The actual root canal length was determined using a no. 8 or no. 10 file into the canal until the tip of the file emerged through the major apical foramen. Differences between EWL and AWL were calculated.

Results: Group I teeth were with root curvature < 20°, group II with 20-36° and group III with >36°. Maximum difference was observed in group III, followed by group II and group I. In group I, the difference was 0.178±0.14 mm, in group II was 0.20±0.22 mm and in group III was 0.24±0.24 mm. The difference was significant (P<0.05).

Conclusion: Curvature of the canal has a small but significant contribution on the accuracy of the EAL tested.