Endodontic length measurements using 3D Endo, cone-beam computed tomography, and electronic apex locator.

Background: The objective of this study is to investigate the accuracy of the 3D Endo software, cone-beam computed tomography (CBCT) software, and the electronic apex locator (EAL) in endodontic length determination.

Methods: 302 root canals in 111 human extracted molars were chosen. Access cavity was performed, and root canal lengths were measured with a digital caliper for actual length (AL) and EAL for electronic length. Teeth were then scanned using CBCT device at voxel size of 0.10 mm. It measured root canal lengths using the CBCT (Romexis Viewer), 3D Endo for proposed length (3D-PL) and correct length (3D-CL). Mean differences between the four methods with the AL were calculated and compared. Fisher's exact test, paired t-test, Bland-Altman plot were used to test the differences among the experimental modalities in working length determination at the significance of 0.05.

Results: The accuracy in the range of ± 0.5 mm of the EAL ProPex II was highest among the experimental modalities, however this method disagreed with the actual length.

Conclusions: The correct working length after adjustment from the semi-automatically length by the 3D Endo software and Romexis Viewer measurements agreed with the AL.