Evaluation of the Radiopacities of Bulk-fill RestorativesUsing Two Digital Radiography Systems

2015 ◽  
Vol 40 (5) ◽  
pp. E197-E205 ◽  
Author(s):  
E Yasa ◽  
B Yasa ◽  
OS Aglarci ◽  
ET Ertas
Keyword(s):  
Digital Radiography ◽  
Complementary Metal Oxide Semiconductor ◽  
American National Standard Institute ◽  
Oxide Semiconductor ◽  
National Standard ◽  
X Ray ◽  
Cmos Sensor ◽  
Photostimulable Phosphor ◽  
The Mean ◽  
Gray Values

SUMMARY This study investigated the radiopacity values of bulk-fill restoratives by using two digital radiography systems. Nine bulk-fill restoratives and a conventional composite were used in the study. Six disc-shaped specimens were prepared from each of these materials, three each at thicknesses of 1 mm and 2 mm, and tooth slices with these same thicknesses were obtained. As a control, an aluminum step wedge varying in thickness from 0.5 to 10 mm in was used. Three specimens of each of the materials, together with the tooth slice and the aluminum step wedge, were placed over a complementary metal oxide semiconductor (CMOS) sensor and a storage photostimulable phosphor (PPS) plate system and exposed using a dental x-ray unit. The images were analyzed using a software program to measure the mean gray values (MGVs). Five measurements were obtained from each of the restorative materials, the enamel, the dentin, and the stepwedge. The MGVs were converted to the equivalent aluminum thicknesses. Three-way analysis of variance (ANOVA) was used to determine the significance of the differences among the groups. A Tukey test was applied for pairwise comparisons (p<0.05). All composite-based restoratives were found to have greater radiopacities than enamel or dentin. Equia Fil had the lowest radiopacity value. Radiopacity increased as the thicknesses of the restorative material increased. The CMOS system showed significantly higher radiopacity values than the PSP system. In conclusion, all investigated bulk-fill restoratives passed the International Organization for Standardization and American National Standard Institute/American Dental Association requirements for radiopacity values when evaluated with the two digital radiography systems.

scholarly journals Analysis of the deterioration of photostimulable phosphor plates

2020 ◽  
Vol 49 (6) ◽  
pp. 20190500
Author(s):  
Gustavo Nascimento de Souza-Pinto ◽  
Gustavo Machado Santaella ◽  
Amanda Achkar Coli ◽  
Anne Caroline Oenning ◽  
Francisco Haiter-Neto
Keyword(s):  
Region Of Interest ◽  
Objective Analysis ◽  
X Rays ◽  
X Ray ◽  
Photostimulable Phosphor ◽  
The Mean ◽  
Phosphor Plates ◽  
Gray Values

Objectives: To assess, objectively to determine the deterioration of the photostimulable phosphor plates (PSPs) after several acquisitions. Methods: Two new PSPs without preliminary use were exposed with an intraoral X-ray unit, and the EXPRESS® (Instrumentarium Imaging, Tuusula, Finland) unit was used for scanning of the PSPs. A 12-stepwedge aluminum scale were used superimposed with the PSPs during the X-rays exposures to perform the objective analyses. Objective analysis was carried out by mean gray values using the Image J software through a region of interest (ROI) of 0.1 × 0.1 mm, and the data were analyzed statistically using ANOVA. Results: For each, the Express® PSP a total of 1800 images were acquired during 60 days. The objective analysis showed loss of the mean gray values between the initial and final images. Besides, the percentage of mean gray values’ loss was between 0.7%, for the thickest step, and 8.4%, for the lowest thickness step. Conclusion: After many X-ray exposures of the Express® PSP a singular deterioration in the mean gray values could be observed.

scholarly journals Complete Ring Artifacts Reduction Procedure for Lab-Based X-ray Nano CT Systems

Sensors ◽  
2021 ◽  
Vol 21 (1) ◽  
pp. 238
Author(s):  
Jakub Šalplachta ◽  
Tomáš Zikmund ◽  
Marek Zemek ◽  
Adam Břínek ◽  
Yoshihiro Takeda ◽  
...  
Keyword(s):  
High Efficiency ◽  
Image Inpainting ◽  
Simulated Data ◽  
Complementary Metal Oxide Semiconductor ◽  
Oxide Semiconductor ◽  
Detection Accuracy ◽  
Reduction Procedure ◽  
X Ray ◽  
Artifacts Reduction ◽  
Ct Data

In this article, we introduce a new ring artifacts reduction procedure that combines several ideas from existing methods into one complex and robust approach with a goal to overcome their individual weaknesses and limitations. The procedure differentiates two types of ring artifacts according to their cause and character in computed tomography (CT) data. Each type is then addressed separately in the sinogram domain. The novel iterative schemes based on relative total variations (RTV) were integrated to detect the artifacts. The correction process uses the image inpainting, and the intensity deviations smoothing method. The procedure was implemented in scope of lab-based X-ray nano CT with detection systems based on charge-coupled device (CCD) and scientific complementary metal–oxide–semiconductor (sCMOS) technologies. The procedure was then further tested and optimized on the simulated data and the real CT data of selected samples with different compositions. The performance of the procedure was quantitatively evaluated in terms of the artifacts’ detection accuracy, the comparison with existing methods, and the ability to preserve spatial resolution. The results show a high efficiency of ring removal and the preservation of the original sample’s structure.

scholarly journals Characterization of dislocations in germanium layers grown on (011)- and (111)-oriented silicon by coplanar and noncoplanar X-ray diffraction

2015 ◽  
Vol 48 (3) ◽  
pp. 655-665 ◽  
Author(s):  
Andrei Benediktovitch ◽  
Alexei Zhylik ◽  
Tatjana Ulyanenkova ◽  
Maksym Myronov ◽  
Alex Ulyanenkov
Keyword(s):  
Dislocation Line ◽  
Complementary Metal Oxide Semiconductor ◽  
Metal Oxide Semiconductor ◽  
Oxide Semiconductor ◽  
Misfit Dislocations ◽  
X Ray Diffraction ◽  
X Ray ◽  
Lattice Constants ◽  
Silicon And Germanium

Strained germanium grown on silicon with nonstandard surface orientations like (011) or (111) is a promising material for various semiconductor applications, for example complementary metal-oxide semiconductor transistors. However, because of the large mismatch between the lattice constants of silicon and germanium, the growth of such systems is challenged by nucleation and propagation of threading and misfit dislocations that degrade the electrical properties. To analyze the dislocation microstructure of Ge films on Si(011) and Si(111), a set of reciprocal space maps and profiles measured in noncoplanar geometry was collected. To process the data, the approach proposed by Kaganer, Köhler, Schmidbauer, Opitz & Jenichen [Phys. Rev. B, (1997),55, 1793–1810] has been generalized to an arbitrary surface orientation, arbitrary dislocation line direction and noncoplanar measurement scheme.

scholarly journals In vitro comparison of two types of digital X-ray sensors for proximal caries detection validated by micro-computed tomography

2020 ◽  
pp. 20200338
Author(s):  
Katrin Heck ◽  
Friederike Litzenburger ◽  
Verena Ullmann ◽  
Lea Hoffmann ◽  
Karl-Heinz Kunzelmann
Keyword(s):  
Exposure Time ◽  
Oxide Semiconductor ◽  
Caries Detection ◽  
Reference Standard ◽  
Micro Computed Tomography ◽  
Perfect Agreement ◽  
Proximal Caries ◽  
X Ray ◽  
Cmos Sensor ◽  
Significant Difference

Objectives: We aimed to compare the diagnostic accuracy of two intraoral digital X-ray sensors—the charged-coupled device (CCD) and complementary metal-oxide-semiconductor (CMOS)—for proximal caries detection in permanent molar and premolar teeth. Micro-CT served as the reference standard. Methods: 250 samples were mounted in three-dimensional (3D)-printed phantoms, and their proximal surfaces were evaluated by ICDAS criteria directly to create a balanced sample. Bitewing radiography was conducted using 3D-constructed X-ray phantoms with a CCD sensor at a 0.08 s and a CMOS sensor at 0.12 and 0.16 s exposure time. Two examiners determined the diagnostic decisions twice at appropriate intervals. Three diagnostic thresholds for sound surfaces and enamel and dentin caries were defined and presented in a cross-table. Sensitivity and specificity values and overall accuracy were calculated, and receiver operating curves were generated and compared. Reliability assessment was performed using linear weighted κ statistics. Results: The overall accuracies between the reference standard and different sensors and exposure times were 63.1% (CCD), 67.1% (CMOS sensor at 0.12 s) and 70.7% (CMOS sensor at 0.08 s). High specificity but low sensitivity values were found for all examination conditions at all thresholds. The area under the curve comparison values revealed no significant difference between sensor types and exposure times. Linear-weighted κ analysis revealed almost perfect agreement for all assessments. Conclusion: No significant difference was found for diagnostic performance of proximal caries detection between the different sensors and exposure times. The increased exposure time did not lead to a significant diagnostic benefit.

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