Accuracy of an Intraoral Digital System for File Length Measurement

Introdouction: Canal length measurement is essential for proper endodontic treatment. Any error or miscalculation in working length determination, particularly in curved canals, can result in complications during or after root canal therapy. Digital radiography has enabled accurate measurement of curved canal length. In this study, we evaluated the accuracy of calibration of a complementary metal oxide semiconductor (CMOS) digital system for file length measurement. Materials and methods: In this in vitro study, 45extracted molar teeth were divided into three groups of 15 with respect to the angle and radius of canal curvature. A 5-mm piece of orthodontic wire was placed on the lateral surface of the roots. Digital radiographs were taken after insertion of the endodontic file by the CMOS digital system. Two observers measured the file length with and without using the calibration tool of digital measurement software. The correlation between observers was evaluated and data were analyzed using the paired t-test with 95% confidence interval. Results: The overall agreement between the observers was satisfactory. There was no significant difference between the mean values of calibrated measurement and true file length with respect to canal curvature (P>0.05). However, there was a significant difference between the mean values of uncalibrated measurement and true file length with respect to canal curvature (P<0.05). Conclusion: The calibrated measurement of file length was more accurate than the uncalibrated file length measurement.