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Background: Delay in the processing of photostimulable phosphor storage plates (PSP) is a common occurrence in crowded clinics. Accordingly, the effects of processing delays in different coverages on the image quality of photostimulable PSPs were investigated with Acteon and Digora scanners. Methods: Three Acteon (group A) and three Digora (group B) PSPs were used in this in vitro study. Each group had three subgroups according to three coverages, including protective box (A1 , B1 ), semitransparent (A2 , B2 ), and original dark case plates (A3 , B3 ). An aluminum step wedge was subjected to constant exposure conditions. The exposed plates were immediately processed with their corresponding scanner device (the golden standard), 5, 10, 20, 30, 40, and 60 minutes after exposure. The average gray level information of the 2nd, 5th, and 8th steps of the Al wedge was considered as the mean gray values (MGVs) of each wedge. The difference between the gray values of the 8th and 2nd steps was measured as image contrast. Results: There was a significant difference between the contrast and MGVs of Acteon and Digora PSPs at all processing delay times (P0.05). In each subgroup, MGVs increased, while contrast decreased by increasing the processing delay time; the difference was significant except for the MGVs in the first 5 minutes of A1 (P=0.12) and A3 (P=0.06). Conclusions: Thus, the type of scanner was effective on image quality; the type of PSP coating in the first few minutes could affect the rate of image quality loss. However, the scan time had a greater effect on the amount of image loss.

Introduction: External root resorption is a clinical problem that is difficult to diagnose, therefore radiographic examination is important for diagnose. The purpose of this study was comparing the diagnostic accuracy of 2 Cone Beam Computed Tomography in detecting of external root resorption, in vitro.Materials & Methods: This study was done on 48 single-rooted teeth. Cavities of 0.3, 0.2 and 0.15 mm in depth with round bur 0.3 mm were drilled on buccal and lingual surfaces in the cervical, middle and apical thirds of some of roots. Then CBCT were taken and 4 observers assessed the scans. Sensitivity, specificity and Kappa value were determined. The statistical analysis was performed with the Z-test (p value < 0.05).Results: In comparison of the accuracy, sensitivity and specificity of the two devices, there was no significant difference. In the apical, middle and cervical as well as at various depths there was no significant difference between the two devices, but in the numerical point of view, the sensitivity for both devices in the midsection, was in the highest amount. The highest value for the specificity is related to the apical region. For both devices, the sensitivity level GBJ, by increasing the depth. The lowest agreement between observers was 0.61. The highest agreement rate was in the middle section and the least amount of agreement was related to the apical region.Conclusion: CBCT brand type is not effective factor in the detection of external root resorption. The location and depth of external root resorption can be effective factors in diagnostic accuracy.

Background. Dental caries is the most important reason for tooth loss. Clinical examination is the most commonly used technique for occlusal caries diagnosis. The diagnostic power of digital systems is a matter of controversy in this field. The present study aimed to determine the diagnostic accuracy of two photostimulable phosphor plate (PSP) systems for early occlusal dentin caries in vitro. Methods. Sixty-nine extracted molar and premolar teeth were used in this study. The teeth were mounted in triple blocks, and standard radiographs were taken by the Digora and Acteon digital radiographic systems. The original and filter 1-enhanced radiographs were evaluated by two experienced observers twice at an interval of two weeks, and dentin caries was recorded in Tables prepared for the study. The teeth were then sectioned in a buccolingual direction and evaluated under a stereomicroscope. The observers’ reports were compared with microscopic findings as the gold standard. SPSS 23 was used to calculate the kappa coefficient, sensitivity, specificity, and area under the ROC curve (AUC). Statistical significance was set at P

nowledge of dental pulp anatomy is effective in preventing random pulp exposure in remedial procedures. This study determined and compared the dimensions of the pulp chamber and the contours of the tooth to the pulp chamber in the first molar teeth on the bite-wing images. The present study was a cross sectional and descriptive one that was performed on 62 bitewing radiographies in the age group of 25-35. Bitewing images were exposed by the oral X-ray machine and processed by the Sordex scanner and 7 anatomical landmarks were measured on these bitewing images in MATLAB. The obtained sizes were analyzed by SPSS 17 and ANOVA was used for statistical computations. The significance level was determined to be P ≤ 0.05. There was a significant difference in the distance between the pulp horns, the height of the pulp chamber, the pulp chamber roof to the place of furcation and the tip of the cusps to the furcation site in the upper and lower jaw (P-value = 0.000). Also, there was a significant difference between the tip of the distal cusp and the distal horn (P-value = 0.050) and the bottom of the pulp chamber to the furcation (P-value = 0.014) in the upper and lower jaw and there was no statistically significant difference between the two jaws only at a distance between the tip of the mesial cusp and the mesial horn (P-value = 0.822). The precise knowledge of the dimensions of the pulp chamber and also the external surfaces of the tooth to the pulp chamber reduced the root canal failure.