scholarly journals Impact of DBBM Fragments on the Porosity of the Calvarial Bone: A Pilot Study on Mice

Materials ◽  
2020 ◽  
Vol 13 (21) ◽  
pp. 4748
Author(s):  
Ulrike Kuchler ◽  
Patrick Heimel ◽  
Alexandra Stähli ◽  
Franz Josef Strauss ◽  
Bernadette Luza ◽  
...  
Keyword(s):  
Morphological Changes ◽  
Histological Evaluation ◽  
Random Allocation ◽  
Bovine Bone ◽  
Distribution Analysis ◽  
Micro Ct ◽  
Micro Computed Tomography ◽  
Calvarial Bone ◽  
Ct Analysis ◽  
Bovine Bone Mineral

Deproteinized bovine bone mineral (DBBM) is brittle and can break into fragments. Here, we examined whether DBBM fragments have an impact on mice calvarial bone during bone augmentation. DBBM was either randomly crushed (DBBM fragments) or left undisturbed (DBBM granules). Then, DBBM fragments or original DBBM granules were placed onto calvarial bone in 20 BALB/c mice. Following random allocation, ten mice received DBBM fragments and ten mice received original DBBM granules. After fourteen days of healing, micro computed tomography (micro-CT) and histological analysis of the augmented sites were performed. The primary outcome was the porosity of the calvarial bone. The micro-CT analysis revealed that DBBM fragments failed to significantly change the porosity of the calvarial bone as compared with original DBBM granules, despite the slightly higher bone resorption in the DBBM fragment group, 10.3% (CI 6.3–11.6) versus 6.1% (CI 4.1–7.8, p = 0.355), respectively. The cortical bone volume was not altered by DBBM fragments as compared with original DBBM granules, i.e., 79.0% (CI 78.9–81.2) versus 81.5% (CI 80.1–83.3, p = 0.357), respectively. The DBBM fragment group revealed similar bone thickness values as compared with the DBBM granules group, i.e., 0.26 mm (CI 0.23–0.29) versus 0.25 mm (CI 0.22–0.27, p = 0.641), respectively. The histological evaluation supported the micro-CT observations, displaying minor signs of porosity and resorption. The particle-size distribution analysis confirmed a shift towards smaller particle sizes in the DBBM fragment group. These findings suggest that DBBM fragments behave similarly to original DBBM granules in terms of bone morphological changes at augmented sites.

scholarly journals A Micro-Computed Tomography Comparison of the Porosity in Additively Fabricated CuCr1 Alloy Parts Using Virgin and Surface-Modified Powders

Materials ◽  
2021 ◽  
Vol 14 (8) ◽  
pp. 1995
Author(s):  
Mirko Sinico ◽  
Suraj Dinkar Jadhav ◽  
Ann Witvrouw ◽  
Kim Vanmeensel ◽  
Wim Dewulf
Keyword(s):  
High Energy ◽  
High Energy Density ◽  
Micro Ct ◽  
Micro Computed Tomography ◽  
Powder Bed ◽  
Metallurgical Defects ◽  
Ct Analysis ◽  
Ct Data ◽  
Surface Modified ◽  
Fusion Pores

Recently, the use of novel CuCr1 surface-modified powder for reliable laser powder-bed fusion (LPBF) manufacturing has been proposed, enabling a broader LPBF processing window and longer powder storage life. Nevertheless, virgin CuCr1 powder is also LPBF processable, on the condition that a high-energy density is employed. In this work, we compare two dense specimens produced from virgin and surface-modified CuCr1 powder. Furthermore, a third sample fabricated from surface-modified powder is characterized to understand an abnormal porosity content initially detected through Archimedes testing. Utilizing high-resolution micro-CT scans, the nature of the defects present in the different samples is revealed. Pores are analyzed in terms of size, morphology and spatial distribution. The micro-CT data reveal that the virgin CuCr1 dense specimen displays keyhole pores plus pit cavities spanning multiple layer thicknesses. On the other hand, the sample fabricated with the surface-modified CuCr1 powder mainly contains small and spherical equi-distributed metallurgical defects. Finally, the CT analysis of the third specimen reveals the presence of a W contamination, favoring lack-of-fusion pores between subsequent LPBF layers. The LPBF melting mode (keyhole or conductive), the properties of the material, and the potential presence of contaminants are connected to the different porosity types and discussed.

Quantitative micro-computed tomography analysis and rheological investigation of Nitrile rubber/Rockwool composites

2021 ◽  
pp. 002199832110338
Author(s):  
Elisson BD da Rocha ◽  
Ana Maria F de Sousa ◽  
Ana Lúcia N da Silva ◽  
Cristina RG Furtado ◽  
Marcos V Colaço ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Elastic Modulus ◽  
Aspect Ratio ◽  
Volume Fraction ◽  
Nitrile Rubber ◽  
Micro Ct ◽  
Micro Computed Tomography ◽  
Rubber Composites ◽  
Ratio Data ◽  
Ct Analysis

This study reports the reinforcement degree investigation of two types of rockwool fibers (F1 and F2), in nitrile rubber composites. The micro-computed tomography (micro-CT) 3D images showed that both fibers were well-dispersed in the NBR matrix, without a preferential orientation. The micro-CT analysis also allowed quantifying volume fraction, inter-fiber distance, and aspect ratio. Those morphometric parameters were used for supporting the composites rheological behavior assessment. Changes in the elastic modulus and phase angle followed the same trend of the inter-fiber distance values, regardless the type of fiber. Both volume fraction and aspect ratio data from the micro-CT analysis were used to predict theoretical values of elastic modulus using the Guth-Gold and modified Guth-Gold equations, and the results obtained were compared to the rheological experimental data. This analysis was helpful to better understand the rockwool fibers reinforcement degree differences in the production of the nitrile rubber composites.

Hypophosphatasia: Evaluation of Size and Mineral Density of Exfoliated Teeth

2016 ◽  
Vol 40 (6) ◽  
pp. 496-502 ◽  
Author(s):  
S Hayashi-Sakai ◽  
N Numa-Kinjoh ◽  
M Sakamoto ◽  
J Sakai ◽  
J Matsuyama ◽  
...  
Keyword(s):  
Density Distribution ◽  
Primary Teeth ◽  
Micro Ct ◽  
Micro Computed Tomography ◽  
Mineral Density ◽  
Normal Range ◽  
Mean Values ◽  
Present Patient ◽  
Ct Analysis ◽  
The Mean

Objective: Most cases of hypophosphatasia (HPP) exhibit early loss of primary teeth. Results of micro-computed tomography (micro-CT) analysis of teeth with HPP have not yet been reported. The purpose of the present study was to describe the size and mineral density distribution and mapping of exfoliated teeth with HPP using micro CT. Study design: Seven exfoliated teeth were obtained from a patient with HPP. Exfoliated teeth sizes were measured on micro CT images and mineral densities of the mandibular primary central incisors were determined. Results: Partial dentures were fabricated for the patient to replace the eight primary teeth which had exfoliated. Most primary teeth sizes were within the normal range. The mean values of enamel and dentin mineral densities in teeth with HPP were 1.35 and 0.88 g/cm3, respectively, in the mandibular primary central incisors. Conclusion: Mineral density distribution and mapping revealed that the values in teeth with HPP were lower than the homonymous teeth controls in all regions from the crown to apex. Furthermore, it was demonstrated that the differences between HPP and controls were larger on the crown side and the differences tended to converge on the apex side. These results suggested that the present patient showed mild hypomineralization in the primary dentition.

scholarly journals Effect of Different Dimensions of Test Samples on the Volumetric Change Assessment Of Endodontic Materials

2021 ◽  
Vol 32 (1) ◽  
pp. 42-47
Author(s):  
Fernanda Ferrari Esteves Torres ◽  
Juliane Maria Guerreiro-Tanomaru ◽  
Jader Camilo Pinto ◽  
Mario Tanomaru-Filho
Keyword(s):  
Morphological Changes ◽  
Micro Ct ◽  
Volume Loss ◽  
Micro Computed Tomography ◽  
Volumetric Change ◽  
Before And After ◽  
Different Dimensions ◽  
The Difference ◽  
The Stability ◽  
Different Diameters

Abstract New methodologies using micro-CT to evaluate solubility besides dimensional and morphological changes of endodontic materials are proposed. However, there is no standardization in the methods. The aim of this study was to assess the effect of different dimensions of test samples on volumetric change evaluation of different endodontic materials. AH Plus, FillCanal and Sealapex root canal sealers, Biodentine, IRM and MTA root-end filling cements were used in the tests. Samples of each material with a thickness of 1.5 mm and different diameters were manufactured: 6.3, 7.75, and 9.0 mm. The samples were scanned in micro-computed tomography (micro-CT) after setting and after 7 days of immersion in distilled water. The volumetric change was evaluated by means of the difference in the total volume of the specimens before and after immersion. Data were submitted to ANOVA and Tukey tests (p<0.05). The size of the samples did not affect the percentage of volumetric change of the materials (p>0.05). All sample sizes had greater volume loss for Sealapex among the sealers and Biodentine for the cements (p<0.05). In conclusion, Biodentine and Sealapex had the highest volume loss after immersion. Samples with 1.5 mm thickness, and diameters ranging between 6.3 and 9.0 mm can be used to assess the stability of endodontic materials using micro-CT without affecting the percentage of volumetric change.

scholarly journals An Ultrasonic Osteotomy Device Enhanced Post-osteotomy Bone Healing Beyond That With a Conventional Rotary Device in a Rat Calvarial Model

2021 ◽  
Author(s):  
Atsushi Danjo ◽  
Reona Aijima ◽  
Reiko U.Yoshimoto ◽  
Shin-Ichi Tanaka ◽  
Takeshi Katsuki ◽  
...  
Keyword(s):  
Bone Healing ◽  
Oral Surgery ◽  
Micro Ct ◽  
Bone Thickness ◽  
Calvarial Bone ◽  
Clinical Benefits ◽  
Ct Analysis ◽  
Rat Calvarial Defect ◽  
The Right ◽  
Ultrasonic Osteotomy

Abstract Ultrasonic osteotomy devices (UODs) have many clinical benefits; for example, they cause little damage to adjacent tissues in oral surgery. However, few reports have focused on bone healing with UODs. This study aimed to compare bone healing after osteotomy with UODs versus rotary osteotomy devices (RODs) in a rat calvarial defect model. Calvarial bone defects were made with a UOD on the right side and an ROD on the left side. Micro-CT analysis revealed that the bone volume was greater with a UOD than with an ROD at 2-3 weeks. In HE-stained sections and micro-CT images, the bone wound gap was closed earlier on the UOD side than on the ROD side. Bone thickness, the quantity of newly formed bone, and the number of osteocytes were greater on the UOD side than on the ROD side. Scanning electron microscopy (SEM) showed that UOD cuts had smoother surfaces than ROD cuts. Osteoblast-like cells harvested from bone chips cut by the UOD had greater proliferative activity than those harvested from ROD-cut bone chips. The use of a UOD may assist bone regeneration, presumably because of osteoblast activation by ultrasonic microvibration and UODs cause less damage to the bone than RODs.

Assessment of the Silver Penetration and Distribution in Carious Lesions of Deciduous Teeth Treated with Silver Diamine Fluoride

2019 ◽  
Vol 53 (4) ◽  
pp. 431-440 ◽  
Author(s):  
Yihong Li ◽  
Yingyi Liu ◽  
Walter J. Psoter ◽  
Olivia M. Nguyen ◽  
Timothy G. Bromage ◽  
...  
Keyword(s):  
Deciduous Teeth ◽  
Micro Ct ◽  
Micro Computed Tomography ◽  
Sem Images ◽  
Dentinal Tubules ◽  
Silver Diamine Fluoride ◽  
Carious Lesions ◽  
Demineralized Enamel ◽  
Sodium Magnesium ◽  
Ct Analysis

The aim of this study was to determine the effects of 38% silver diamine fluoride (SDF) on carious lesions of human deciduous teeth. Ten extracted deciduous incisors with caries were collected and treated with SDF. After the treatment, the teeth were sectioned through the center of the carious lesion. The extent of sliver precipitation was examined using quantitative backscattered electron scanning electron microscopy (qBSE-SEM), energy-dispersive X-ray spectroscopy (EDX), and micro-computed tomography (micro-CT). The qBSE-SEM images revealed that the silver particles could penetrate through the pellicle complex, along with the rod sheaths into the demineralized enamel rods and the dentinal tubules, and form silver-enriched barriers surrounding the carious lesions at depths up to 2,490.2 μm (mean 744.7 ± 448.7 μm) within the dentinal tubules of the carious lesions, but less likely in the sound enamel. The EDX spectrum analysis revealed that carbon, oxygen, phosphorus, chlorine, silver, and calcium were the main elements detected in the lesions treated with SDF. Additionally, sodium, magnesium, aluminum, silicon, zinc, sulfur, and fluorine were detected as the minor elements within the SDF precipitation “zone.” The micro-CT analysis further showed that in the deep cavitated lesions, the silver precipitation could be observed in the pulp chamber. These findings provide new evidence defining the SDF mode of action for arresting caries and suggest that the application of a highly concentrated SDF solution on deciduous teeth should be used with caution for various carious lesions.

scholarly journals Effect of Various Types of Muscle Contraction with Different Running Conditions on Mouse Humerus Morphology

Life ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 284
Author(s):  
Kaichi Ozone ◽  
Yuichiro Oka ◽  
Yuki Minegishi ◽  
Takuma Kano ◽  
Takanori Kokubun ◽  
...  
Keyword(s):  
Bone Formation ◽  
Muscle Contraction ◽  
Morphological Changes ◽  
Control Level ◽  
Volume Ratio ◽  
Tartrate Resistant Acid Phosphatase ◽  
Micro Ct ◽  
Micro Computed Tomography ◽  
Bone Morphology ◽  
Attachment Region

How various types of muscle contraction during exercises affect bone formation remains unclear. This study aimed to determine how exercises with different muscle contraction types affect bone morphology. In total, 20 mice were used and divided into four groups: Control, Level, Down Slow, and Down. Different types of muscle contraction were induced by changing the running angle of the treadmill. After the intervention, micro-computed tomography (Micro-CT), tartrate-resistant acid phosphatase/alkaline phosphatase (ALP) staining, and immunohistochemical staining were used to analyze the humerus head, tendon-to-bone attachment, and humerus diaphyseal region. Micro-CT found that the volume ratio of the humeral head, the volume of the tendon-to-bone attachment region, and the area of the humeral diaphyseal region increased in the Down group. However, no difference was detected in bone morphology between the Level and Down Slow groups. In addition, histology showed activation of ALP in the subarticular subchondral region in the Down Slow and Down groups and the fibrocartilage region in the tendon-to-bone attachment. Moreover, Osterix increased predominantly in the Down Slow and Down groups.Overall bone morphological changes in the humerus occur only when overuse is added to EC-dominant activity. Furthermore, different type of muscle contractile activities might promote bone formation in a site-specific manner.

scholarly journals Micro-CT Analysis of Morphological Changes in Mandibles of Growing Rats with Unilateral Occlusal Elevation

2019 ◽  
Vol 13 (1) ◽  
pp. 150-158
Author(s):  
Takahiro Morohoshi ◽  
Takenobu Ishii ◽  
Munetada Ishikawa ◽  
Daehwan Choi ◽  
Dai Ariizumi ◽  
...  
Keyword(s):  
Morphological Changes ◽  
Three Dimensional ◽  
Growth Period ◽  
Control Group ◽  
Micro Computed Tomography ◽  
Growing Rats ◽  
Male Wistar Rats ◽  
Ct Analysis ◽  
Long Term Observation ◽  
Removal Group

Objectives: This study investigated the effect of unilateral occlusal elevation in the molar region on facial and mandibular development in growing rats. Materials and Methods: Thirty 5-week-old male Wistar rats were randomly allocated to three groups (n = 10). The control group was allowed to develop naturally until 9 weeks of age. A device fitted on the caused unilateral occlusal elevation at 5 weeks in the removal group. The device was removed at 7 weeks and the rats were observed until 9 weeks. In the continuation group, the same device fitted on the left-side molars caused unilateral occlusal elevation continuously for 9 weeks. All groups underwent craniofacial scanning with three-dimensional micro-computed tomography at 5, 7, and 9 weeks. Results: In the removal and continuation groups, the mandible was displaced to the unelevated side. At 7 weeks, both these groups showed greater skeletal growth and molar extrusion on the elevated side, with significant differences between the elevated and unelevated sides. At 9 weeks, there were significant differences in both skeletal and alveolar growth between these groups; the asymmetry ameliorated in the removal group. Limitations: We evaluated three-dimensional morphometry by fitting a device to rat molars for a short observation period; thus, future studies are warranted to acquire data following long-term observation. Conclusion: Unilateral occlusal elevation during the growth period suppressed molar eruption and extrusion on the elevated and unelevated sides, respectively. The height of the mandibular ramus increased on the elevated side, resulting in asymmetric growth.

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