Evaluation of a digital measurement tool to estimate working length in endodontics.

The purpose of the study was to compare the segmental measurement tool from the Shick Technologies CDR digital system with the conventional film radiography measurement technique to determine preoperative working length. Natural extracted human teeth with varying degrees of root curvature were used. All teeth were imaged using the Shick Technologies CDR direct digital system and conventional E-speed film. Measurements from digital radiography and conventional film were compared with measurements made directly from the endodontic files. The Wilks' Lambda multivariate test was used. The mean measurement of each modality was compared with the other and with the gold standard. The test showed statistically significant differences between the two modalities at p<0.05. The mean measurements for both modalities were not significantly different from the gold standard. The modality most closely approaching the gold standard was the conventional film.