Influence of Apical Periodontitis on the Accuracy of Three Electronic Root Canal Length Measurement Devices: An In Vivo Study

Thirty-two single-rooted teeth scheduled for extraction, consisting of 16 teeth with AP and 16 teeth with normal periapex (NP), were selected. Access cavity was prepared and coronal portion of the canal was flared. Electronic working length (EWL) was determined by each ERCLMD according to each manufacturer's instructions. Each tooth was extracted and actual working length (AWL) was determined by inserting a size 15 K-file until the tip could be seen at a position tangential to the major foramen and then 0.5 mm was subtracted from the measurement. The distance from the AWL to the file tip was calculated and compared between the two groups by t-test. The accuracy of each ERCLMD within ±0.5 mm was compared between the groups by Fisher's test. Statistical significance was set at P < .05.