Detection of Marginal Leakage of Class V Restorations In Vitro by Micro–Computed Tomography

2014 ◽  
Vol 39 (2) ◽  
pp. 174-180 ◽  
Author(s):  
XY Zhao ◽  
SB Li ◽  
LJ Gu ◽  
Y Li
Keyword(s):  
Computed Tomography ◽  
Resin Composite ◽  
Nitrate Solution ◽  
Three Dimensional ◽  
Micro Ct ◽  
Micro Computed Tomography ◽  
Class V ◽  
Enamel Structure ◽  
Significant Difference

SUMMARY This in vitro study evaluated the efficacy of micro–computed tomography (CT) in marginal leakage detection of Class V restorations. Standardized Class V preparations with cervical margins in dentin and occlusal margins in enamel were made in 20 extracted human molars and restored with dental bonding agents and resin composite. All teeth were then immersed in 50% ammoniacal silver nitrate solution for 12 hours, followed by a developing solution for eight hours. Each restoration was scanned by micro-CT, the depth of marginal silver leakage in the central scanning section was measured, and the three-dimensional images of the silver leakage around each restoration were reconstructed. Afterward, all restorations were cut through the center and examined for leakage depth using a microscope. The silver leakage depth of each restoration obtained by the micro-CT and the microscope were compared for equivalency. The silver leakage depth in cervical walls observed by micro-CT and microscope showed no significant difference; however, in certain cases the judgment of leakage depth in the occlusal wall in micro-CT image was affected by adjacent enamel structure, providing less leakage depth than was observed with the microscope (p<0.01). Micro-CT displayed the three-dimensional image of the leakage around the Class V restorations with clear borders only in the dentin region. It can be concluded that micro-CT can detect nondestructively the leakage around a resin composite restoration in two and three dimensions, with accuracy comparable to that of the conventional microscope method in the dentin region but with inferior accuracy in the enamel region.

Three-Dimensional Quantification of Calcium Salt-Composite Resorption (CSC) In Vitro by Micro-computed Tomography (Micro-CT)

JOM ◽  
2014 ◽  
Vol 66 (4) ◽  
pp. 559-565 ◽  
Author(s):  
T. Winkler ◽  
X. Y. Dai ◽  
G. Mielke ◽  
S. Vogt ◽  
H. Buechner ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Calcium Salt ◽  
Three Dimensional ◽  
Micro Ct ◽  
Micro Computed Tomography

scholarly journals Influence of the calcium hydroxide paste vehicle on penetration into lateral canals

2018 ◽  
Vol 21 (3) ◽  
pp. 282
Author(s):  
Amanda Sousa Vidal ◽  
Daniele Aparecida Leão ◽  
Fernanda Mota Guimarães ◽  
Mariana Oliveira Gonçalves ◽  
Raissa Freitas Pinheiro ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Calcium Hydroxide ◽  
Propylene Glycol ◽  
Group Analysis ◽  
Distilled Water ◽  
Micro Ct ◽  
Micro Computed Tomography ◽  
Respective Group ◽  
Before And After

<p><strong>Objective: </strong>The aim of this study was to use Micro computed tomography (micro-CT) to evaluate the influence of the type of vehicle associated with calcium hydroxide on its ability to penetrate simulated lateral canals. <strong>Materials and methods:</strong> 30 acrylic blocks with simulated lateral canals comprising apical, middle and cervical thirds were used in the <em>in vitro</em> study. The blocks were divided into 3 groups (n = 10) according to the type of vehicle used (chlorhexidine, distilled water and propylene glycol) in the calcium hydroxide slurry, which was inserted in the respective group of simulated canals with a K# 30 file and then agitated with an ultrasonic tip. The blocks were scanned by micro-computed tomography (micro-CT) before and after insertion of the medication. The images obtained were reconstructed and analyzed to obtain the initial volume of lateral canals and the volume of medication that penetrated into them. <strong>Results:</strong> In the intragroup analysis, both distilled water and chlorhexidine 2% were observed to present statistical difference in all thirds of the canal. Propylene glycol showed no intragroup difference. In the inter-group analysis, the propylene glycol paste presented higher values of penetration into the simulated lateral canals than the other groups (p &lt;0.05). <strong>Conclusion:</strong> Propylene glycol used as vehicle of the calcium hydroxide paste provided better penetration results in simulated lateral canals.</p>

scholarly journals PEG-modified gadolinium nanoparticles as contrast agents for in vivo micro-CT

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Charmainne Cruje ◽  
P. Joy Dunmore-Buyze ◽  
Eric Grolman ◽  
David W. Holdsworth ◽  
Elizabeth R. Gillies ◽  
...  
Keyword(s):  
Contrast Agent ◽  
Contrast Agents ◽  
Soft Tissues ◽  
Three Dimensional ◽  
Blood Pool ◽  
Micro Ct ◽  
Micro Computed Tomography ◽  
Poly Ethylene

AbstractVascular research is largely performed in rodents with the goal of developing treatments for human disease. Micro-computed tomography (micro-CT) provides non-destructive three-dimensional imaging that can be used to study the vasculature of rodents. However, to distinguish vasculature from other soft tissues, long-circulating contrast agents are required. In this study, we demonstrated that poly(ethylene glycol) (PEG)-coated gadolinium nanoparticles can be used as a vascular contrast agent in micro-CT. The coated particles could be lyophilized and then redispersed in an aqueous solution to achieve 100 mg/mL of gadolinium. After an intravenous injection of the contrast agent into mice, micro-CT scans showed blood pool contrast enhancements of at least 200 HU for 30 min. Imaging and quantitative analysis of gadolinium in tissues showed the presence of contrast agent in clearance organs including the liver and spleen and very low amounts in other organs. In vitro cell culture experiments, subcutaneous injections, and analysis of mouse body weight suggested that the agents exhibited low toxicity. Histological analysis of tissues 5 days after injection of the contrast agent showed cytotoxicity in the spleen, but no abnormalities were observed in the liver, lungs, kidneys, and bladder.

Flowable Composites as “Filled Adhesives:” A Microleakage Study

2004 ◽  
Vol 5 (4) ◽  
pp. 32-41 ◽  
Author(s):  
Luis Guilherme Sensi ◽  
Fabiano Carlos Marson ◽  
Sylvio Monteiro ◽  
Luiz Narciso Baratieri ◽  
Mauro Amaral Caldeira de Andrada
Keyword(s):  
Tap Water ◽  
Resin Composite ◽  
Control Group ◽  
Single Bond ◽  
Class V ◽  
Group I ◽  
Significant Difference ◽  
Group 2 ◽  
Flowable Composites

Abstract Objective The purpose of this in vitro study was to investigate the microleakage at dentin margins of a flowable resin composite associated with an adhesive, either light cured separately or co-cured, in Class V cavities. Materials and Methods Twenty four recently extracted human molars were prepared with standardized boxshaped Class V cavities of 3.0 mm (mesial-distal), 2.0 mm (occlusal-gingival), and 2.0 mm depth with margins located on enamel and dentin/cementum on the buccal or lingual surfaces. The cavities were randomly assigned into three groups (n=8): Group I – Single Bond + Filtek Z250 (control); Group II – Single Bond + Filtek Flow (light cured separately) + Filtek Z250; and Group III – Single Bond + Filtek Flow co-cured (light cured simultaneously) + Filtek Z250. After being immersed in tap water for 24 h, the specimens were thermocycled (1000x, 5°-55°C, 30 sec dwell time) and immersed in a 0.5% basic fuchsine solution for 24 h. The restorations were sectioned longitudinally and gingival margins were evaluated for microleakage using a 0-4 scale. Data were subjected to the Kruskal-Wallis test at p<0.05. Results A statistically significant difference at p = 0.0044 between Groups 1 and 3 and Groups 2 and 3 was observed. Although Group 2 performed slightly better than Group 1, no significant difference was observed. Conclusion The use of a flowable resin composite cured simultaneously with an adhesive yielded the worst results in this study. As no statistical differences were seen between Groups 1 and 2, the use of a flowable composite as a means of minimizing microleakage at dentin margins may be questioned. Citation Sensi LG, Marson FC, Monteiro S Jr., Baratieri LN, de Andrada MAC. Flowable Composites as “Filled Adhesives:” A Microleakage Study . J Contemp Dent Pract 2004 November;(5)4:032-041.

scholarly journals Micro-CT study of Middle Ordovician Spumellaria (radiolarians) from western Newfoundland, Canada

2020 ◽  
Vol 94 (3) ◽  
pp. 417-435 ◽  
Author(s):  
Sarah Kachovich ◽  
Jonathan C. Aitchison
Keyword(s):  
Computed Tomography ◽  
Three Dimensional ◽  
Detailed Examination ◽  
Micro Ct ◽  
Micro Computed Tomography ◽  
Lower Paleozoic ◽  
X Ray ◽  
Middle Ordovician ◽  
Radiolarian Assemblage ◽  
Taxonomic Groups

AbstractA new, previously undescribed Middle Ordovician (middle Darriwilian: Dw2) radiolarian assemblage has been recovered from the Table Cove Formation at Piccadilly Quarry, western Newfoundland. Constituents of the fauna described herein are both distinctive and exceptionally well preserved. Three-dimensional X-ray micro-computed tomography (μ-CT) is used to make a detailed examination of four key spumellarian specimens. This technology enables visualization of hitherto ambiguous details of the internal morphologies of key lower Paleozoic taxonomic groups, among which a lack of knowledge has impeded resolution of higher taxonomic rankings.

scholarly journals Micro-computed tomography: A novel diagnostic technique for the evaluation of gastrointestinal specimens

2021 ◽  
Vol 09 (12) ◽  
pp. E1886-E1889
Author(s):  
Noboru Kawata ◽  
Alexei Teplov ◽  
Peter Ntiamoah ◽  
Jinru Shia ◽  
Meera Hameed ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Three Dimensional ◽  
Diagnostic Technique ◽  
Human Colon ◽  
Ffpe Tissue ◽  
Micro Ct ◽  
Micro Computed Tomography ◽  
Cross Sectional ◽  
Tissue Samples ◽  
Formalin Fixed Paraffin Embedded

AbstractMicro-computed tomography (micro-CT) is a non-destructive modality that can be used to obtain high-resolution three-dimensional (3 D) images of the whole sample tissue; the usefulness of micro-CT has been reported for evaluation of breast cancer and lung cancer. However, this novel diagnostic technique has never been used for evaluating endoscopically resected gastrointestinal specimens. In the present study, we scanned 13 formalin-fixed paraffin-embedded (FFPE) tissue blocks of a normal human colon and gastric tissue samples using micro-CT. The evaluation comprised a comparison of the acquired whole block images with the images of the corresponding cross-sectional slice of the hematoxylin and eosin-stained slide. Micro-CT was able to produce images of the whole sample and clearly depict tissues such as glandular structures, muscularis mucosae, and blood vessels in the FFPE tissue blocks of normal gastrointestinal samples. Furthermore, the 3 D reconstructed could be used to create a cross-sectional image and reflected the surface structure of samples obtained from any site. Micro-CT has the potential to become a highly promising pathological diagnostic assistance tool for endoscopically resected gastrointestinal specimens in combination with conventional microscopic examination.

Upscaling Reservoir Rock Porosity by Fractal Dimension Using Three-Dimensional Micro-Computed Tomography and Two-Dimensional Scanning Electron Microscope Images

2020 ◽  
Vol 143 (1) ◽  
Author(s):  
Muhammad Jawad Munawar ◽  
Sandra Vega ◽  
Chengyan Lin ◽  
Mohammad Alsuwaidi ◽  
Naveed Ahsan ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Three Dimensional ◽  
Fractal Dimensions ◽  
Two Dimensional ◽  
Micro Ct ◽  
Micro Computed Tomography ◽  
Sandstone Sample ◽  
The Core ◽  
Carbonate Sample ◽  
Scanning Electron

Abstract Scaling porosity of sedimentary rocks from the scale of measurement to the scale of interest is still a challenge. Upscaling of porosity can assist to accurately predict other petrophysical properties of rock at multiple scales. In this study, we use the two-dimensional (2D) scanning electron microscope (SEM) and three-dimensional (3D) X-ray micro-computed tomography (micro-CT) image to upscale porosity from the image scale to the core plug scale. A systematic imaging plan is deployed to capture rock properties of a carbonate and a sandstone sample, which are sensitive to the fractal nature of these rocks. Image analysis records wider pore spectrum (0.12–50 µm) in the carbonate sample than in sandstone (0.12–30 µm). The fractal dimensions are also higher in the carbonate than in the sandstone sample. Median, volume-weighted average of pore radius, and fractal dimensions derived from the image analysis are used as inputs in this equation. The results of the present study using this equation yielded to the best results on a resolution of 2.5 µm/voxel in the sandstone and 2.01 µm/voxel resolution in the carbonate sample for 3D micro-CT images, where fractal-scaling porosity matches well with the porosity measured at the core plug scale. The 2D SEM images provided a good estimation of porosity in the sandstone sample, where micro-CT imaging techniques could not capture the full pore spectrum. The fractal porosity equation showed promising results and offers a potential alternative way to estimate porosity when there are no routine core measurements available.

scholarly journals Comparison of Two Techniques for Selection of Master Gutta-Percha Cone Using Micro-Computed Tomography

2013 ◽  
Vol 24 (4) ◽  
pp. 367-370 ◽  
Author(s):  
Joao Manoel Silva-Filho ◽  
Aline Evangelista Souza-Gabriel ◽  
Graziela Bianchi Leoni ◽  
Samuel Henrique Camara De-Bem ◽  
Edson Alfredo ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Conventional Technique ◽  
Filling Material ◽  
Micro Ct ◽  
Micro Computed Tomography ◽  
Root Canals ◽  
Gutta Percha ◽  
Working Length ◽  
Significant Difference ◽  
Material Volume

This study used micro-computed tomography (micro-CT) to evaluate the fit of the master gutta-percha cone at time of cone fit, gutta-percha volume in the filling material, and the filling material volume in relation to the canal at the apical limit of the working length. Root canals of 20 maxillary central incisors were prepared with rotary instruments and distributed into two groups (n=10). The gutta-percha cone tip was either plasticized (apical thermal impression technique - ATI) or not (conventional technique - CT), and its apical fit was checked. The apical 1 mm of working length was examined with a micro-CT, canals were filled with gutta-percha and sealer, and new micro-CT scans were obtained. In CT, gutta-percha filled 35.83 ± 15.05% of the canal at cone selection and 38.72 ± 11.64% after filling. In ATI, these values were 23.14 ± 7.74% and 26.98 ± 20.40%, respectively. Gutta-percha volume in the filling material, and filling material volume in relation to the canal were, respectively, 61.28 ± 11.64% and 87.76 ± 9.98% for CT, and 73.00 ± 20.41% and 89.96 ± 9.08% for ATI. No significant difference was found between cone selection and after canal filling, for either CT (p=0.593) or ATI (p=0.4975). The techniques did not differ significantly with respect to gutta-percha volume in the filling material (p=0.132) and filling material volume in relation to the canal (p=0.612). An ideal fit of the master gutta-percha cone at working length was not achieved regardless of the cone selection technique, and the material-filled area was similar for both techniques.

scholarly journals Evaluation of scaffold microstructure and comparison of cell seeding methods using micro-computed tomography-based tools

2020 ◽  
Vol 17 (165) ◽  
pp. 20200102
Author(s):  
Aleksi Palmroth ◽  
Sanna Pitkänen ◽  
Markus Hannula ◽  
Kaarlo Paakinaho ◽  
Jari Hyttinen ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Three Dimensional ◽  
3D Cell Culture ◽  
Adipose Derived Stem Cells ◽  
Micro Ct ◽  
Cell Seeding ◽  
Micro Computed Tomography ◽  
Tissue Engineering Scaffolds ◽  
Scaffold Architecture ◽  
Static Seeding

Micro-computed tomography (micro-CT) provides a means to analyse and model three-dimensional (3D) tissue engineering scaffolds. This study proposes a set of micro-CT-based tools firstly for evaluating the microstructure of scaffolds and secondly for comparing different cell seeding methods. The pore size, porosity and pore interconnectivity of supercritical CO 2 processed poly( l -lactide-co- ɛ -caprolactone) (PLCL) and PLCL/β-tricalcium phosphate scaffolds were analysed using computational micro-CT models. The models were supplemented with an experimental method, where iron-labelled microspheres were seeded into the scaffolds and micro-CT imaged to assess their infiltration into the scaffolds. After examining the scaffold architecture, human adipose-derived stem cells (hASCs) were seeded into the scaffolds using five different cell seeding methods. Cell viability, number and 3D distribution were evaluated. The distribution of the cells was analysed using micro-CT by labelling the hASCs with ultrasmall paramagnetic iron oxide nanoparticles. Among the tested seeding methods, a forced fluid flow-based technique resulted in an enhanced cell infiltration throughout the scaffolds compared with static seeding. The current study provides an excellent set of tools for the development of scaffolds and for the design of 3D cell culture experiments.

scholarly journals Marginal and Internal Adaptation Evaluation of Dental Composites Using Micro-CT

2019 ◽  
Vol 2019 ◽  
pp. 1-6
Author(s):  
Adrian Tudor Stan ◽  
Laura Cîrligeriu ◽  
Laura Idorași ◽  
Meda Lavinia Negruțiu ◽  
Cosmin Sinescu ◽  
...  
Keyword(s):  
Composite Resin ◽  
Resin Composite ◽  
Three Dimensional ◽  
Ct Scanning ◽  
Dental Composite ◽  
Micro Ct ◽  
Gap Formation ◽  
Micro Computed Tomography ◽  
Vertical Slot ◽  
Internal Adaptation

The aim of the study was to determine the marginal and internal adaptation after curing of different composite resin restorations, using a nondestructive X-ray micro-computed tomography (micro-CT). Forty previously extracted human molars, kept in 10% formalin to preserve the bonding capabilities of the tooth structures, were divided into four groups based on the composite system used and different light-curing times. Class II (vertical slot) cavities were prepared on one proximal side and restored with dental composite using a Tofflemire matrix, with a bulk-fill composite resin (Venus Bulk Fill, Heraeus Kulzer) and a universal posterior composite (G-ænial Posterior, GC). A curing lamp (Kerr Demi Ultra) was used with different curing times. Micro-CT scanning was performed by using Nikon XTH 225ST to reveal any defects in adaptation or gaps at the tooth restoration interface. The 3D images of the adaptation around the restorations were reconstructed using VG Studio Max 2.2 and myVGL 2.2.6 64-bit software. All samples from the G-ænial group showed marginal and internal gaps, with G-ænial Posterior having higher polymerization shrinkage and marginal gap values. In the Venus Bulk Fill group, there were fewer restorations with internal and external gap formation. Micro-CT is a three-dimensional imaging technique that can nondestructively detect adaptation around the resin composite restorations at every level of the sample.

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