A comparative histomorphological and micro computed tomography study of the primary stability and the osseointegration of The Sydney Mini Screw; a qualitative pilot animal study in New Zealand rabbits

2018 ◽  
Vol 41 (4) ◽  
pp. 360-369
Author(s):  
Anastasia Bakopoulou ◽  
Peter Hoang ◽  
Ali Fathi ◽  
Matthew Foley ◽  
Colin Dunstan ◽  
...  
Keyword(s):  
Computed Tomography ◽  
New Zealand ◽  
Animal Study ◽  
Primary Stability ◽  
Bone Graft Substitute ◽  
Micro Computed Tomography ◽  
Combined Use ◽  
New Zealand Rabbits

SummaryObjectiveThe aim of this study was to assess the potential of improving orthodontic miniscrews’ (MSs) primary stability in vivo by evaluating the dispersion capacity of an injectable bone graft substitute (iBGS) through a newly designed hollow MS [The Sydney Mini Screw (SMS)] and its integration with the cortical and trabecular bone by using the femur and tibia in a New Zealand rabbit animal model.MethodsIn total, 24 MSs were randomly placed in each proximal tibia and femur of 6 New Zealand rabbits with an open surgery process. Aarhus MSs were used as controls and the effect of injection of iBGS was studied by implanting SMSs with and without iBGS injection. The dispersion of iBGS and the integration of the SMS were studied by using micro Computed Tomography (μCT) and histochemical analysis at two time points, 0 day and 8 weeks post-implantation.ResultsiBGS was successfully injected through the SMS and hardened in situ. After 8 weeks, μCT results revealed that the iBGS particles were resorbed and bone tissue was formed around the SMS and within its lateral exit holes.ConclusionsThis pilot animal study showed the high potential of the combined use of iBGS and SMS as a newly developed technique to promote the primary stability of MSs.

Advanced measurement techniques for braided composite structures: A review of current and upcoming trends

2020 ◽  
Vol 54 (25) ◽  
pp. 3895-3917 ◽  
Author(s):  
Garrett W Melenka ◽  
Cagri Ayranci
Keyword(s):  
Computed Tomography ◽  
Strain Measurement ◽  
Composite Structures ◽  
Measurement Methods ◽  
Micro Computed Tomography ◽  
Braided Composites ◽  
Optical Strain Measurement ◽  
In Situ Strain Measurement ◽  
Optical Strain

Braiding is an advanced textile manufacturing method that is used to produce two-dimensional and three-dimensional components. Unlike laminated structures, braids have interlaced yarns that form a continuity between layers. This structure allows for improved impact resistance, damage tolerance, and improved through-thickness reinforcement. Despite the numerous advantages of braided composites, braids also have shortcomings. Their highly complex fiber architecture presents challenges in the availability and choice of the strain measuring and characterization techniques. Advanced measurement methods such as optical strain measurement, micro-computed tomography, and in situ strain measurement are required. Optical strain measurement methods such as digital image correlation and high-speed imaging are necessary to accurately measure the complex deformation and failure that braided composites exhibit. X-ray-based micro-computed tomography measurements can provide detailed geometric and morphologic information for braided structures, which is necessary for accurately predicting the mechanical properties of braided structures. Finally, in situ strain measurement methods will provide detailed information on the internal deformation and strain that exists within braided structures. In situ sensors will also allow for in-service health monitoring of braided structures. This paper provides a detailed review of the aforementioned sensing technologies and their relation to the measurement of braided composite structures.

scholarly journals Damaging HMX/HTPB formulations: In-situ compression imaging using X-ray micro computed tomography

2015 ◽  
Author(s):  
Brian M. Patterson ◽  
Nikolaus Lynn Cordes ◽  
Bryce C. Tappan ◽  
Darla Graff Thompson ◽  
Virginia Warren Manner
Keyword(s):  
Computed Tomography ◽  
Micro Computed Tomography ◽  
X Ray

scholarly journals An apparently non-swinging tentorium in the Diplopoda (Myriapoda): comparative morphology of the tentorial complex in giant pill-millipedes (Sphaerotheriida)

ZooKeys ◽  
2018 ◽  
Vol 741 ◽  
pp. 77-91 ◽  
Author(s):  
Leif Moritz ◽  
Thomas Wesener ◽  
Markus Koch
Keyword(s):  
Computed Tomography ◽  
Comparative Morphology ◽  
Head Size ◽  
Micro Computed Tomography ◽  
Posterior Process ◽  
Large Head

The presence of a swinging tentorium is a key apomorphy of Myriapoda, but this character has been studied in detail in only few species. Here the tentorium, i.e., the peristomatic skeleton of the preoral chamber, is comparatively studied in three species of the millipede order Sphaerotheriida Brandt, 1833. Since dissections of the fragile tentorial components proved to be difficult, despite the large head size, they were analysed mainly in situ via micro-computed tomography. Our results confirm previous observations of large differences in the tentorial construction in the giant pill-millipedes compared to chilognathan diplopods. The tentorium of Sphaerotheriida consists of a curved, plate-like epipharyngeal bar with distal projections, an elongate and thin hypopharyngeal bar, and a plate-like triangular posterior process; a transverse bar is absent. Only seven muscles attach at the tentorium in giant pill-millipedes, including two antennal muscles and two muscles of the gnathochilarium. Within the order Sphaerotheriida, the composition of the tentorium and its muscular equipment seems to be conserved, except for some variability in the shape of the epipharyngeal bar. As the transverse bar has been considered essential for the mobility of the tentorium in myriapods, its absence in Sphaerotheriida may indicate that their tentorium is not capable of performing a swing. Loss of tentorial mobility may also pertain to the order Glomerida Brandt, 1833, inferred here from the absence of a posterior process. An apparently immobile tentorium in Glomerida and Sphaerotheriida can straightforwardly be correlated with transformations of the head related to their ability of volvation. The different transformations of the tentorium, here hypothesised to cause immobility, may support current assumptions that the ability of volvation evolved convergently in Glomerida and Sphaerotheriida. This conclusion, however, still requires more detailed studies of the head anatomy in Glomerida and Glomeridesmida Cook, 1895.

Demineralized bone matrix-based microcarrier scaffold favors vascularized large bone regeneration in vivo in a rat model

2018 ◽  
Vol 33 (2) ◽  
pp. 182-195 ◽  
Author(s):  
Qiannan Li ◽  
Wenjie Zhang ◽  
Guangdong Zhou ◽  
Yilin Cao ◽  
Wei Liu ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Stem Cells ◽  
Bone Marrow ◽  
Bone Regeneration ◽  
Demineralized Bone Matrix ◽  
Bone Matrix ◽  
Matrix Group ◽  
Micro Computed Tomography ◽  
Demineralized Bone

Insufficient neo-vascularization of in vivo implanted cell-seeded scaffold remains a major bottleneck for clinical translation of engineered bone formation. Demineralized bone matrix is an ideal bone scaffold for bone engineering due to its structural and biochemical components similar to those of native bone. We hypothesized that the microcarrier form of demineralized bone matrix favors ingrowth of vessels and bone regeneration upon in vivo implantation. In this study, a rat model of femoral vessel pedicle-based bone engineering was employed by filling the demineralized bone matrix scaffolds inside a silicone chamber that surrounded the vessel pedicles, and to compare the efficiency of vascularized bone regeneration between microcarrier demineralized bone matrix and block demineralized bone matrix. The results showed that bone marrow stem cells better adhered to microcarrier demineralized bone matrix and produced more extracellular matrices during in vitro culture. After in vivo implantation, microcarrier demineralized bone matrix seeded with bone marrow stem cells formed relatively more bone tissue than block demineralized bone matrix counterpart at three months upon histological examination. Furthermore, micro-computed tomography three-dimensional reconstruction showed that microcarrier demineralized bone matrix group regenerate significantly better and more bone tissues than block demineralized bone matrix both qualitatively and quantitatively (p < 0.05). Moreover, micro-computed tomography reconstructed angiographic images also demonstrated significantly enhanced tissue vascularization in microcarrier demineralized bone matrix group than in block demineralized bone matrix group both qualitatively and quantitatively (p < 0.05). Anti-CD31 immunohistochemical staining of (micro-) vessels and semi-quantitative analysis also evidenced enhanced vascularization of regenerated bone in microcarrier demineralized bone matrix group than in block demineralized bone matrix group (p < 0.05). In conclusion, the microcarrier form of demineralized bone matrix is an ideal bone regenerative scaffold due to its advantages of osteoinductivity and vascular induction, two essentials for in vivo bone regeneration.

scholarly journals Intraosteal Behavior of Porous Scaffolds: The mCT Raw-Data Analysis as a Tool for Better Understanding

Symmetry ◽  
2019 ◽  
Vol 11 (4) ◽  
pp. 532 ◽  
Author(s):  
Parrilla-Almansa ◽  
González-Bermúdez ◽  
Sánchez-Sánchez ◽  
Meseguer-Olmo ◽  
Martínez-Cáceres ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Mathematical Analysis ◽  
Demineralized Bone Matrix ◽  
Bone Matrix ◽  
Hounsfield Unit ◽  
In Vivo Studies ◽  
Porous Scaffolds ◽  
Micro Computed Tomography ◽  
Radiological Analysis

The aim of the study is to determine the existing correlation between high-resolution 3D imaging technique obtained through Micro Computed Tomography (mCT) and histological-histomorphometric images to determine in vivo bone osteogenic behavior of bioceramic scaffolds. A Ca-Si-P scaffold ceramic doped and non-doped (control) with a natural demineralized bone matrix (DBM) were implanted in rabbit tibias for 1, 3, and 5 months. A progressive disorganization and disintegration of scaffolds and bone neoformation occurs, from the periphery to the center of the implants, without any differences between histomorphometric and radiological analysis. However, significant differences (p < 0.05) between DMB-doped and non-doped materials where only detected through mathematical analysis of mCT. In this way, average attenuation coefficient for DMB-doped decreased from 0.99 ± 0.23 Hounsfield Unit (HU) (3 months) to 0.86 ± 0.32 HU (5 months). Average values for non-doped decreased from 0.86 ± 0.25 HU (3 months) to 0.66 ± 0.33 HU. Combination of radiological analysis and mathematical mCT seems to provide an adequate in vivo analysis of bone-implanted biomaterials after surgery, obtaining similar results to the one provided by histomorphometric analysis. Mathematical analysis of Computed Tomography (CT) would allow the conducting of long-term duration in vivo studies, without the need for animal sacrifice, and the subsequent reduction in variability.

Feasibility, Safety, and Efficacy of Flow-Diverting Stent-Assisted Microsphere Embolization of Fusiform and Sidewall Aneurysms

Neurosurgery ◽  
2015 ◽  
Vol 77 (1) ◽  
pp. 126-136 ◽  
Author(s):  
Andrea Nonn ◽  
Stefanie Kirschner ◽  
Giovanna Figueiredo ◽  
Martin Kramer ◽  
Omid Nikoubashman ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Protection System ◽  
Micro Computed Tomography ◽  
Beam Hardening ◽  
Safety And Efficacy ◽  
Aneurysm Occlusion ◽  
Flow Diverting Stent ◽  
Microsphere Embolization

Abstract BACKGROUND: Treatment of wide-necked internal carotid artery aneurysms is frequently associated with incomplete occlusion and high recurrence rates. Furthermore, platinum coils cause strong beam-hardening artifacts, hampering subsequent image analyses. OBJECTIVE: To assess the feasibility, safety, and efficacy of flow-diverting, stent-assisted microsphere embolization of fusiform and sidewall aneurysms in vitro and in vivo. METHODS: Using a recirculating pulsatile in vitro flow model, 5 different aneurysm geometries (inner/outer curve, narrow/wide neck, and fusiform) were treated (each n = 1) by flow-diverting stent (FDS) implantation and subsequent embolization through a jailed microcatheter using calibrated microspheres (500–900 μm) larger than the pores of the FDS mesh. Treatment effects were analyzed angiographically and by micro computed tomography. The fluid of the in vitro model was filtered to ensure that no microspheres evaded the aneurysm. The experiment was repeated once in vivo. RESULTS: In vitro, all 5 aneurysms were safely and completely occluded by FDS-assisted microsphere embolization. Virtually complete aneurysm occlusion was confirmed by angiography and micro computed tomography. No microspheres escaped into the circulation. The experiment was successfully repeated in 1 pig with a sidewall aneurysm generated by vessel occlusion. An embolic protection system placed distally of the FDS in vitro and in vivo (each n = 1) contained no microspheres after the embolization. Thus, no microspheres were lost in the circulation, and the use of an embolic protection system seems feasible to provide additional safety. CONCLUSION: FDS-assisted microsphere embolization of fusiform and sidewall aneurysms is feasible and yields virtually complete aneurysm occlusion while avoiding coil-associated beam-hardening artifacts.

Monitoring and quantifying formation of tissue engineered human bone in situ by micro-computed tomography

2006 ◽  
Vol 39 ◽  
pp. S218
Author(s):  
H. Hagenmüller ◽  
T. Kohler ◽  
S. Hofmann ◽  
H.P. Merkle ◽  
L. Meinel ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Human Bone ◽  
Micro Computed Tomography
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