Radiological accuracy in the interpretation of apical fitness in endodontics


Aim: To compare the accuracy of right–angle paralleling and bisecting–angle radiographictechniques in the determination of apical fitness in endodontic therapy. Materials and Methods:Thirty three root canals of first upper and lower molar teeth have been used in this study. A K–filewas inserted into the canal until its tip was fit snuggly one millimeter shorter than the apex. Eachtooth then radiographed twice by the right–angle paralleling and bisecting–angle techniques. Thedistance between the file tip and the center of radiographical apex was directly measured by twoexaminers and the mean of each two measurements was recorded. Data were collected and analyzedstatistically by analysis of variance and Duncan’s Multiple Range test. Results: The mean valuerevealed that there were clear differences between the mean of measurements by the paralleltechnique (0.87mm) and that with the bisecting technique (0.39mm), when these two resultscompared with the mean of real measurements (1mm). One way analysis of variance revealed therewere significant differences in one of the three groups at p < 0.05 level. Duncan’ Multiple Range testshowed that the parallel measurements when compared with the real measurements the results showed that there was no significant difference but was significantly different from the bisecting measurements. Conclusion: It is preferable to the dentist to use the right–angle paralleling technique during root canal treatment, where it gives more accurate result for estimation of the working length.