In‑vitro comparison of four different working length determination techniques

Aim The aim of this study was to compare four different working length determination techniques. Materials and methods Fifty extracted single‑canaled anterior teeth were decoronated. The root canals’ working lengths were repetitively determined in five groups (n = 50 each) using regular radiographic film (group 1), digital radiographic image (group 2), cone‑beam computed tomographic image (group 3), electronic apex locator (group 4) and direct measurement (group 5, control) by subtracting 0.5 mm from the length of # 15 k‑file visible at the apical foramen. The collected data was statistically analyzed using both analysis of variance and least significant difference (LSD) comparisons at P value less than or equal to 0.05. Results The one‑way analysis of variance indicated a difference between the data of study groups (P = 0.011). The LSD comparisons revealed a longer working length (LSD, P ≤ 0.05) in groups 1 and 2 than groups 3 and 5 (control). On the other hand, No difference (LSD, P 0.05) was detected between the working length in groups 3 and 4 in comparison with group 5 (control). Conclusion The electronic apex locator and the cone‑beam computed tomography are more accurate techniques to determine root canal’s working length than the normal and the 2D digital radiographs.