Accuracy of Working Length Determination in Root Canal Treatment Using Different Algorithms

Determination of working length has great significance in root canal treatments. For this purpose, analog radiography has been replaced by digital radiography. Despite numerous studies, there is still no accurate information about the resolution of these images. The aim of this study was to assess the accuracy of working length determination in root canal treatment using different algorithms in digital radiography. Using an analytical-diagnostic method, an access cavity was prepared in 36 mandibular and maxillary premolar teeth. A file # 15 was inserted into the canal of each tooth until the tip of the file was observed, then the files were retracted 0.5 mm. The teeth were then placed in an acrylic block, and finally, a radiograph was taken of the blocks. Thereafter, the file in each canal was taken out and measured using a digital caliper. The obtained measurement was the real length of the file. The saved images underwent modifications using different algorithms of image processing. The working length was observed on a monitor under standard conditions. Data were analyzed by t- test using SPSS (ver. 17). Based on the findings of this study, no significant difference was observed between the main image, the images processed with the emboss, enhancement, sharpen, and negative algorithms, and the actual file size regarding the means of error. None of the indices had a statistically significant difference with the actual file length (P > 0.05). According to the results of this study, the accuracy of the file length in improved digital images showed no significant difference in comparison with the actual file length.