[ effect of developer age the diagnostic accuracy of endodontic files' length]

Radiography has extensive applications in root canal treatment and the developer age plays an important role in making a definite diagnosis. The present study examined the effect of developer age on the diagnostic accuracy of endodontic file length measurement using D-speed, E-speed and E/F-speed films. In this diagnostic study, radiographs were processed weekly by a developer aged for up to 6 weeks. Radiographs were viewed by 5 postgraduate students of endodontics and oral radiology. They determined the file tip position using a 3-point confidence scale. The area under the curve [Az] was calculated and used as a diagnostic accuracy scale. The effects of film type and endodontic file size were analyzed by one-way ANOVA, Tukey's post hoc test and Student's t test. E-speed and D-speed films had similar diagnostic accuracy higher than that of E/F speed film [P<0.0001]. The Az values of D, E and E/F speed films were 0.5882, 0.5538 and 0.3578, in fresh developer, 0.5782, 0.5718 and 0.3498 in 2-week old developer and 0.6196, 0.6724 and 0.2080, in 4-week old developer solution, respectively. Developer age did not decrease the diagnostic accuracy of D and E-speed films but decreased that of E/F films at 4 weeks. Radiographs processed with 6 weeks old developer were not readable. All observers showed higher diagnostic accuracy determining the size of file # 15 than 10 [P<0.0001]. The mean Az values for endodontic file sizes 10 and 15 using fresh, 2-week and 4-week old developers were 0.3984 and 0.6016, 0.3732, and 0.6268 and 0.2774 and 0.7226, respectively. The developer aged for up to 4 weeks did not significantly affect the diag-nostic accuracy of D-speed and E-speed films. E/F speed films cannot be used with de-velopers older than 2 weeks and their usage was associated with lower accuracy compared to E and D-speed films

ability of panoramic radiography in determining the relationship of mandibular third molar roots with the inferior alveolar canal

Panoramic radiography is the preoperative imaging technique of choice for impacted mandibular third molar surgery. However, controversy exists regarding the ability of panoramic radiography in determining the relationship of the mandibular third molar roots with the inferior alveolar canal. This study aimed to assess the ability of panoramic radiography in determining the relationship of mandibular third molar roots with the inferior alveolar nerve [IAN] canal. This diagnostic accuracy study was conducted on 100 panoramic radiographs that were evaluated by 5 oral and maxillofacial surgery residents. They offered their expert opinion on the relationship of third molars with the IAN canal based on panoramic radiographs. These perspectives were compared with the actual post-surgical findings. Kappa and weighted Kappa reproducibility tests were used for data analysis. Among 100 understudy cases, physical contactbetween the mandibular third molar roots and the canal was not observed in 88 cases intra-operatively; while this relationship existed in 12 cases. The panoramic radiography had a diagnostic sensitivity of 83.3%, specificity of 83%, positive predictive value of 40% and negative predictive value of 97.3%. The overall accuracy was 85%. Kappa and weighted Kappa coefficients of reproducibility were 61% and 79%, respectively. Panoramic radiography can be confidently used as the most reliable and commonly accessible imaging technique. Considering the obtained negative predictive value, panoramic radiography is capable of revealing the involvement of third molar roots with the IAN canal with 97.3% accuracy. Panoramic radiography had a low diagnostic value in determining the morphology of roots