scholarly journals Perspectives of the Tooth Restoration Technology Based on the Computed Tomography Data

2018 ◽  
Vol 155 ◽  
pp. 01004
Author(s):  
Maxim Putrik ◽  
Vladimir Ivanov ◽  
Igor Antsygin
Keyword(s):  
Computed Tomography ◽  
Processing System ◽  
Cone Beam ◽  
Tooth Surface ◽  
X Rays ◽  
Micro Computed Tomography ◽  
X Ray ◽  
Tomography Method ◽  
Cone Beam Tomography ◽  
Tomography Data

The aim of the study is to create an image processing system, which allows dentists to create tooth surface automatically. X-rays images of jaws from the cone beam tomography or the spiral computed tomography and images from the micro-computed tomography are the initial data for processing. Example of using the combination of optical and x-ray images in the dentistry is described. Also, it was shown how to use the microcomputed tomography method to plan the placement of orthopedic structures on the lost teeth sites.

scholarly journals Designing and Fabricating Nano-Structured and Micro-Structured Radiation Shields for Protection against CBCT Exposure

Materials ◽  
2020 ◽  
Vol 13 (19) ◽  
pp. 4371 ◽  
Author(s):  
Kiana Nikeghbal ◽  
Zahra Zamanian ◽  
Shoaleh Shahidi ◽  
Gianrico Spagnuolo ◽  
Parisa Soltani
Keyword(s):  
Computed Tomography ◽  
Weight Ratio ◽  
Dioctyl Phthalate ◽  
Cone Beam ◽  
Linear Attenuation Coefficient ◽  
X Rays ◽  
X Ray ◽  
Nano Material ◽  
Radiation Shields ◽  
Shielding Properties

Researchers have always been interested in finding new and effective materials for protection against radiation. This experimental study aimed to design and fabricate new types of nano-material and micro-material based shields against the ionizing effect of cone beam computed tomography (CBCT) X-rays. To fabricate a flexible prototype, we added dioctyl phthalate (DOP) oil to emulsion polyvinyl chloride (PVC) powder. The paste was mixed and dispersed. Then, nano- and micro-powders of WO3 and Bi2O3 were added to the paste, with the weight ratio of 20% PVC, 20% DOP, and 60% nano- and micro-metals. Using an ultrasonic mixer, the polymer matrix and metals were mixed and a paste with a thick texture was developed. The resultant paste was poured into glass molds and the molds were then heated in an oven. After cooling, the resultant sheets were selected for further experiments. A CBCT unit and dosimeter were used to evaluate the characterization and X-ray shielding properties of the fabricated prototypes. The half-value layers (HVL) for nano-WO3, micro-WO3, nano-Bi2O3, and micro-Bi2O3 were 0.0390, 0.0524, 0.0351, and 0.0374 cm, respectively. In addition, the linear attenuation coefficient (µ) for these materials were 17.77, 13.20, 19.71, and 18.5 cm−1, respectively. The findings indicate that nano-structured samples are more effective in the attenuation of X-ray energy. The nano-structured WO3 prototype was nearly 34% more efficient in attenuating radiation compared to the micro-structured WO3 prototype. This difference in nano- and micro-structured Bi2O3 prototypes was 6.5%.

Non-Destructive Assaying Gold Jewellery Using Dual-Energy Micro-Computed Tomography

2015 ◽  
Vol 73 (3) ◽  
Author(s):  
Jaafar Abdullah ◽  
Abibullah Samsudin ◽  
Nor Laili Omar ◽  
Hafizza Abdul Manan
Keyword(s):  
Computed Tomography ◽  
Matrix Effects ◽  
Visual Observation ◽  
Dual Energy ◽  
Micro Computed Tomography ◽  
Tomographic Images ◽  
X Ray ◽  
Challenging Tasks ◽  
Tomography Method ◽  
Non Destructive

Determining the fineness of gold jewelleries remains one of the most challenging tasks in gold trading. The existing technology of gold testing is inadequate, allowing gold counterfeiting worldwide. The most popular non-destructive method for analysis of gold jewelleries is X-ray fluorescence technique. However, the technique is limited to surface only and it is also greatly influenced by matrix effects. In this paper, dual-energy X-ray micro-computed tomography method was proposed to assay gold jewelleries. Experimental results demonstrated that grey values of reconstructed tomographic images in combination with advanced image analysis procedures could be used to detect fake jewelleries. Due to the uniqueness of X-ray absorption, the technique was also capable of identifying different materials in gold jewelleries. Further analysis on sectioned-earrings samples using X-ray diffraction techniques and visual observation confirmed all tomographic findings.  

scholarly journals Grains, grids and mineral surfaces: approaches to grain-scale matrix modeling based on X-ray micro-computed tomography data

2019 ◽  
Vol 1 (10) ◽  
Author(s):  
Urban Svensson ◽  
Paolo Trinchero ◽  
Michel Ferry ◽  
Mikko Voutilainen ◽  
Björn Gylling ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Mineral Surfaces ◽  
Micro Computed Tomography ◽  
X Ray ◽  
Matrix Modeling ◽  
Scale Matrix ◽  
Tomography Data

Typical errors when performing intraoral periapical x-rays, and their effect on image quality

2020 ◽  
pp. 36-44
Author(s):  
A.P. Arzhantsev
Keyword(s):  
Computed Tomography ◽  
Image Quality ◽  
Digital Image ◽  
Cone Beam ◽  
X Rays ◽  
Post Processing ◽  
X Ray ◽  
Selection Of ◽  
Periapical Radiography

During the study, intraoral periapical images were analyzed in 300 patients. The possibilities of using the methods of radiography and their influence on the quality of the obtained x-ray images were studied. The intraoral periapical radiography was compared with the results of orthopantomography and cone beam computed tomography. To identify the features of the mapping of zones of periapical destruction, 47 experimental x-ray studies were performed on skeletonized jaws with artificial defects in cortical plates. Often encountered errors are: an arbitrary choice of angles of inclination and the centration of the x-ray tube, the wrong location of the x-ray receiver in the patient's mouth, inaccurate installation or poor fixation of the patient's head, inefficient selection of physical and technical conditions of shooting, non-compliance with the conditions of the photo process with analog radiography or post-processing and printing digital image. The characteristic projection distortions of images resulting from these errors are analyzed and illustrated.

scholarly journals Analysis of Sn-Bi Solders: X-ray Micro Computed Tomography Imaging and Microstructure Characterization in Relation to Properties and Liquid Phase Healing Potential

Materials ◽  
2020 ◽  
Vol 14 (1) ◽  
pp. 153
Author(s):  
Georg Siroky ◽  
Elke Kraker ◽  
Jördis Rosc ◽  
Dietmar Kieslinger ◽  
Roland Brunner ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Liquid Phase ◽  
Elastic Anisotropy ◽  
Primary Phase ◽  
Micro Computed Tomography ◽  
X Ray ◽  
Microstructural Parameters ◽  
Semi Solid ◽  
Tomography Data ◽  
Mean Intercept Length

This work provides an analysis of X-ray micro computed tomography data of Sn-xBi solders with x = 20, 30, 35, 47, 58 wt.% Bi. The eutectic thickness, fraction of eutectic and primary phase are analyzed. Furthermore, the 3D data is evaluated by means of morphology parameters, such as, shape complexity, flatness, elongation and mean intercept length tensor. The investigated alloys are categorized in three groups based on their morphology, which are described as “complex dominant”, “complex- equiaxed” and “mixed”. The mechanical behavior of Sn-Bi alloys in the semi-solid configuration and the correlation with microstructural parameters are discussed. A varying degree of geometric anisotropy of the investigated alloys is found through the mean intercept length tensor. Representative volume element models for finite element simulations (RVE-FEM) are created from tomography data of each alloy to analyze a correlation of geometric and elastic anisotropy. The simulations reveal an elastic isotropic behavior due to the small difference of elastic constants of primary and eutectic phase. A discussion of properties in the semi-solid state and liquid phase healing is provided.

scholarly journals DLSR: a solution to the parallax artefact in X-ray diffraction computed tomography data

2020 ◽  
Vol 53 (6) ◽  
pp. 1531-1541
Author(s):  
A. Vamvakeros ◽  
A. A. Coelho ◽  
D. Matras ◽  
H. Dong ◽  
Y. Odarchenko ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Tomographic Reconstruction ◽  
Scale Up ◽  
Lattice Parameter ◽  
Chemical Information ◽  
X Rays ◽  
X Ray Diffraction ◽  
Major Barrier ◽  
X Ray ◽  
Tomography Data

A new tomographic reconstruction algorithm is presented, termed direct least-squares reconstruction (DLSR), which solves the well known parallax problem in X-ray-scattering-based experiments. The parallax artefact arises from relatively large samples where X-rays, scattered from a scattering angle 2θ, arrive at multiple detector elements. This phenomenon leads to loss of physico-chemical information associated with diffraction peak shape and position (i.e. altering the calculated crystallite size and lattice parameter values, respectively) and is currently the major barrier to investigating samples and devices at the centimetre level (scale-up problem). The accuracy of the DLSR algorithm has been tested against simulated and experimental X-ray diffraction computed tomography data using the TOPAS software.

scholarly journals A Novel Method for Clinical Cochlear Duct Length Estimation toward Patient-Specific Cochlear Implant Selection

OTO Open ◽  
2018 ◽  
Vol 2 (4) ◽  
pp. 2473974X1880023 ◽  
Author(s):  
Daniel Schurzig ◽  
Max Eike Timm ◽  
Cornelia Batsoulis ◽  
Rolf Salcher ◽  
Daniel Sieber ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Cone Beam Computed Tomography ◽  
Cochlear Implantation ◽  
Tertiary Care ◽  
Current Trend ◽  
Cone Beam ◽  
Patient Specific ◽  
Micro Computed Tomography ◽  
Temporal Bones ◽  
Tomography Data

Objective In the field of cochlear implantation, the current trend toward patient-specific electrode selection and the achievement of optimal audiologic outcomes has resulted in implant manufacturers developing a large portfolio of electrodes. The aim of this study was to bridge the gap between the known variability of cochlea length and this electrode portfolio. Design Retrospective analysis on cochlear length and shape in micro–computed tomography and cone beam computed tomography data. Setting Tertiary care medical center. Subjects and Methods A simple 2-step approach was developed to accurately estimate the individual cochlear length as well as the projected length of an electrode array inside the cochlea. The method is capable of predicting the length of the cochlea and the inserted electrode length at any specific angle. Validation of the approach was performed with 20 scans of human temporal bones (micro–computed tomography) and 47 pre- and postoperative clinical scans (cone beam computed tomography). Results Mean ± SD absolute errors in cochlear length estimations were 0.12 ± 0.10 mm, 0.38 ± 0.26 mm, and 0.71 ± 0.43 mm for 1, 1.5, and 2 cochlea turns, respectively. Predicted insertion angles based on clinical cone beam computed tomography data showed absolute deviations of 27° ± 18° to the corresponding postoperative measurements. Conclusion With accuracy improvements of 80% to 90% in comparison with previously proposed approaches, the method is well suited for the use in individualized cochlear implantation.

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