Evaluation of the effects of processing delays and protective plastic cases on image quality of a photostimulable phosphor plate system

This ex vivo study evaluated the quality of digital radiographic images obtained with the photostimulable phosphor plate system (Digora) according to the processing delay and maintenance of optical plates in either opaque (supplied with the system) or transparent protective plastic cases during this period. Five radiographs were obtained from the mandibular molar region of a dry human mandible using optical plates. These plates were placed in the protective plastic cases before obtaining the radiographs and were processed immediately or after processing delays of 5, 60 and 120 min, when the case was removed. The results revealed a reduction in image quality when processing was delay 120 min compared to the other times. The opaque case provided better protection to the sensor than the transparent case. In conclusion, a 120-min processing delay for the Digora system caused a reduction in image quality, yet without interfering with the quality of diagnosis. The opaque case supplied by the system's manufacturer provided better protection to the optical plate than the transparent case.

Comparison of radiographic measurements obtained with conventional an indirect digital imaging during endontic treatment

The aims of this study were to evaluate the quality of indirect digitized radiographic images taken during endodontic procedures and to compare the measurements recorded with this technique to those obtained from conventional radiographs. Two-hundred conventional periapical radiographs taken at the undergraduate Endodontics Clinic of the Dental School of Bauru were digitized. The conventional and indirect digitized images were compared by three examiners as to the quality and accuracy of the measurements recorded during endodontic treatment, in canal length determination, gutta-percha adaptation, lateral condensation and final obturation. The conventional radiographs were observed on a film viewer, surrounded by a dark card, and measured with magnifying glass and a millimeter ruler; the indirect digitized images were evaluated on the Digora® for Windows software, with free utilization of the bright/contrast tool. Unlike the conventional radiographic images, all indirect digitized images were considered as having a high quality. The distance between the filling material and the root apex was 0.117 mm larger, on average, for the Digora® system (p<0.01). The measurements achieved by the investigated radiographic methods were clinically similar and they are thus equivalent. Changes in brightness and contrast of the images using Digora®software improved the diagnosis.

Consideration of density matching technique of the plate type direct radiologic image system and the conventional X-ray film: first step for the subtraction / 대한치주과학회지

Digital substraction technique and computer-assisted densitometirc analysis detect minor change in bone density and thus increase the diagnostic accuracy. This advantage as well as high sensitivity and objectivity which precludes human bias have drawn interest in radiologic research area. The objectives of this study are to verify if Radiographic density can be recognized in linear pattern when density profile of standard periapical radiograph with the aluminium stepwedge as the reference, was investigated under varies circumstances which can be encountered in clinical situations, and in addition to that to obtain mutual relationship between the existing standard radiographic system, and future digital image systems, by confirming the corelationship between the standard radiograph and Digora system which is a digital image system currently being used. In order to make quantitative analysis of the bone tissue, digital image system which uses high resolution automatic slide scanner as an input device, and Digora system were compared and analyzed using multifunctional program, Brain3dsp. The following conclusions were obtained. 1. Under common clinical situation that is 70kVp, 0.2 sec., and focal distance 10cm, Al-Equivalent image equation was found to be Y=11.21X+46.62 r(2)=0.9898 in standard radiographic system, and Y=12.68X+74.59, r(2)=0.9528 in Digora system, and linear relation was confirmed in both the systems. 2. In standard radiographic system, when all conditions were maintained the same except for the condition of developing solution, Al-Equivalent image equation was Y=10.07X+41.64, r(2)=0.9861 which shows high corelationship. 3. When all conditions were maintained the same except for the Kilovoltage peak, linear relationship was still maintained under 60kVp, and Al-Equivalent image equation was Y=14.60X+68.86, r(2)=0.9886 in the standard radiograhic system, and Y=13.90X+80.68, r(2)=0.9238 in Digora system. 4. When all conditions were maintained the same except for the exposure time which was varied from 0.01 sec. to 0.8 sec., Al-Equivalent image equation was found to be linear in both the standard radiographic system and Digora system. The R-square was distributed from 0.9188 to 0.9900, and in general, standard radiographic system showed higher R-square than Digora system. 5. When all conditions were maintained the same except for the focal distance which was varied from 5cm to 30cm, Al-Equivalent image equation was found to be linear in both the standard radiographic system and Digora system. The R-square was distributed from 0.9463 to 0.9925, and the standard radiographic system had the tendency to show higher R-square in shorter focal distances.

Detectability of Ektaspeed Puls Film, Digitized and Digora Images for artificial periapical bone lesions / 대한구강악안면방사선학회지

The comparative detectability of the artificial periapical defects among Ektaspeed Plus film, digitized and digora images was evaluated. The artificail defects were made in the cancellous bone and cancellous-cortical junction with the size of 1.0x0.8mm2, 1.4x1.1mm2 and 2.8x2.2mm2. The defects in cancellous-cortical junction extended into cortical bone with the depth of 0, 0.5 and 1.0 mm. The results were as follows : 1. In junctional defects Ektaspeed Plus film for 2.8x12.2mm2 defect showed the highest detectability. But siginificant difference were only found between Ektaspeed Plus films and digitized images(p<0.05). 2. Almost all defects within cacellous bone were not detected except a few digitized and Digora images for the size of 2.8x2.2mm2. Digora images for them showed significant differences with Ektaspeed Plus films and digitized images(p<0.05). 3. The sensitinity of all imaging modalities were 0.9 or 1.0 in junctional defects for the size of 1.4x2.2mm2 and 2.8x2.2mm2. For cancellous defects, Digora image showed the highest sensitivity of 0.6 for the size of 2.8x2.2mm2. 4. Siginificant differences for change of exposure time were found in most group of Ektaspeed Plus films and digitized images(p<0.05). But there was no significant differences in Digora images for cacellous defects.

The accuracy of the radiographic method in root canal length measurement / 대한구강악안면방사선학회지

For the successful endodontic treatment, root canal should be cleaned thoroughly by accurate mechanical and chemical canal preparation and sealed completely with canal filling material without damaging the periapical tissues. The accuracy of the root canal length measurement is a prerequisite for the success of the endodontic treatment, and the root canal length is often determined by the standard periapical radiographs and digital tactile sense. In this study, the accuracy and the clinical usefulness of Digora(R), an intraoral digital imaging processor and the conventional standard radiographs were compared by measuring the length from the top of the file to the root apex. 30 single rooted premolars were invested in a uniformly sized blocks and No.25 K-file was inserted into and fixed in each canal. Each block was placed in equal distance and position to satisfy the principle of the bisecting angle and paralleling techniques and Digora(R) system's image and standard periapical radiographs were taken. Each radiograph was examined by 3 different observers by measuring the length from top of the file to the root apex and each data was compared and analyzed. The results were as follows; 1. In the bisecting angle technique, the average difference between the Digora(R) system and standard periapical radiograph was 0.002 mmand the standard deviation was 0.341 mmwhich showed no statistically significant difference between the two systems(p>0.05). Also, in the paralleling technique, the average difference between these two system was 0.007 mmand the standard deviation was 0.323 mmwhich showed no statistically significant difference between the two systems(p>0.05). 2. In Digora(R) system, the average difference between the bisecting angle and paralleling technique was -0.336 mmand the standard deviation was 0.472 mmwhich showed a statistically significant difference between the two techniques(p 3. In Digora(R) system and the standard periapical radiographs, there was a statistically significant difference between the measurement using the bisecting angle technique and the actual length(p0.05). In conclusion, the determination of the root canal length by using the Digora(R) system can give us as good an image as the standard periapical radiograph and using the paralleling technique instead of the bisecting angle technique can give a measurement closer to the actual canal length, thereby contributing to a successful result. Also, considering the advantages of the digital imaging processor such as decreasing the amount of exposure to the patient, immediate use of the image, magnification of image size, control of the contrast and brightness and the ability of storing the image can give us good reason to replace the standard periapical radiographs.