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Background and Objective: Early diagnosis of internal root resorption is a challenge in endodontics. Image-processing filters are applied to facilitate image interpretation for diagnostic or treatment purposes. The aim of this study was to investigate the effect of contrast alterations in detecting internal root resorption in CBCT images. Materials and Methods: Fifty single root teeth with were splited mesiodistally in this in vitro case-control study. Artificial internal resorption lesions were created in cervical, middle or apical areas. CBCT images were taken before and after cavity preparation. CBCT images was evaluated by two radiologists in low, intermediate and high contrasts. The data were analyzed using Kappa and MacNemar tests on SPSS software. Overall accuracy was evaluated with sub curve analysis of ROC. Results: Low contrast images had the highest sensitivity, specificity and overall accuracy (all 100% for first observer and 92, 100, 96% for second observer, respectively). In apical area in low, intermediate and high contrasts, sensitivity, specificity and overall accuracy were 100%. There was a significant difference with reality in high contrast-cervical resorption group (P=0.016). Conclusion: The low contrast may be an acceptable processing filter in detection of internal root resorption. [ABSTRACT FROM AUTHOR]

Background and Objectives: periapical lesions in a clinical problem is that there are often difficulties in detecting it. Since the diagnosis of periapical lesions in the periapical radiolucency on the observation area، so the diagnosis of periapical radiographic evaluation is important .The Target of this study is to assess the diagnostic exactness of indirect digital radiography (PSP) and the conventional processing in diagnosis of periapical lesions at invitro conditions. Subjects and Methods: In this experimental - laboratory research، 60 synthetic lesions were formed under the apex of teeth using of single-root premolar teeth placed in the dried Mandible bone of sheep. These lesions were taken radiographs by two methods of digital and conventional. Two oral and maxillofacial radiologists examined the presence or absent of lesions in PSP pictures by conventional and reverse processing in each tooth. Results: The average sensitiveness of observers in PSP radiography with conventional processing in mm1، 0mm/5، mm%25 are 46%، 63.5%، and 93.3% respectively which were reduced to 45%، 60% and 86.6% with PSP radiography of reverse processing. Digital radiography with conventional processing has the characteristics of (66%) in comparison with the (63.3%) digital radiography of reverse processing. Conclusion: There is no significant difference between the sensitiveness of digital radiography with conventional and reverse processing. [ABSTRACT FROM AUTHOR]

Background and Objectives: Accurate identification of landmarks of lateral cephalometric radiographic is important for analysis. The objective of this study was to investigate the effects of digital image processing filters on detection of lateral cephalometric landmarks. Subjects and Methods: Lateral cephalometric radiographs were acquired from 30 patients. The unprocessed images and those processed using Shadow، Sharpen، Negative and 3D Emboss filters were assessed by two observers and scored for clarity of points A، B، N، Orbitale، Pronasal، Subnasal، Pogonion' and Menton'. The results were statistically analyzed using Friedman and Wilcoxon tests. Results: For detection of points N، Orbitale and Pronasal، 3d emboss filter had the lowest rating and the other methods were not significantly different. For detection of points A، Subnasal، Pogonion' and Menton'، 3d emboss and negative filters had the lowest rating and these two filters were not significantly different and the other methods were not significantly different. For point B all methods were not significantly different. Conclusions: The results of this study clearly showed that processing of lateral cephalometric radiographs with different filters does not necessarily lead to improvement of the image but a wrong selection algorithms and filters may reduce the diagnostic quality of the images. [ABSTRACT FROM AUTHOR]

Background and Objective: Recently، most digital imaging systems provide the option of image post-processing with different techniques. This clinical study aims to compare these techniques on perception of anatomical structures and overall image quality in direct digital panoramic radiographs. Subjects and Methods: Panoramic radiographs were acquired from 45 patients. The original and the processed images using shadow، sharpen، sigmoidal or exponential، Negative and 3D embossed filters were assessed by 4 observers and scored for perception of the floor of maxillary sinus، dentino enamel junction، root canal space، periodontal ligament space، inferior mandibular cortex، bone trabecular pattern، inferior alveolar canal and overall image quality. The results were statistically analyzed using Friedman and Wilcoxon tests. Results: The best diagnostic quality in all anatomical structures and overall image quality was obtained using sharpen processing method. The negative filter earned the second place in floor of maxillary sinus، dentine -enamel junction and root canal space. The original images provided the second best diagnostic quality in periodontal ligament space، inferior mandibular cortex، bone trabecular pattern، inferior alveolar canal and overall image quality. Conclusions: To perceive the anatomical structures and overall image quality the sharpened image processing method is recommended. It should be noted that the processing techniques should be chosen carefully considering the anatomical structure that is being studied. [ABSTRACT FROM AUTHOR]