Simulation of Impact Test for Determining “Health” of Percutaneous Bone Anchored Implants

2006 ◽  
Vol 128 (5) ◽  
pp. 647-653 ◽  
Author(s):  
S. Jones ◽  
G. Faulkner ◽  
D. Raboud ◽  
K. Fyfe ◽  
J. Wolfaardt
Keyword(s):  
Connective Tissue ◽  
Hearing Aids ◽  
Impact Testing ◽  
Height Loss ◽  
Element Analysis ◽  
Connective Tissue Layer ◽  
Noninvasive Technique ◽  
Detailed Model ◽  
Implant Abutment ◽  
Bone Margin

There is an ongoing requirement for a clinically relevant, noninvasive technique to monitor the integrity of percutaneous implants used for dental restorations, bone-anchored hearing aids, and to retain extra-oral prostheses (ear, eye, nose, etc). Because of the limitations of conventional diagnostic techniques (CT, MRI), mechanical techniques that measure the dynamic response of the implant-abutment system are being developed. This paper documents a finite element analysis that simulates a transient response to mechanical impact testing using contact elements. The detailed model allows for a specific interface between the implant and bone and characterizes potential clinical situations including loss of bone margin height, loss of osseointegration, and development of a soft connective tissue layer at the bone-implant interface. The results also show that the expected difference in interface stiffness between soft connective tissue and osseointegrated bone will cause easily measurable changes in the response of the implant/abutment system. With respect to the loss of bone margin height, changes in the order of 0.2mm should be detectable, suggesting that this technique is at least as sensitive as radiography. A partial loss of osseointegration, while not being as readily evident as a bone margin loss, would still be detectable for losses as small as 0.5mm.

scholarly journals The Symmetric 3D Organization of Connective Tissue around Implant Abutment: A Key-Issue to Prevent Bone Resorption

Symmetry ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 1126
Author(s):  
Giovanna Iezzi ◽  
Francesca Di Lillo ◽  
Michele Furlani ◽  
Marco Degidi ◽  
Adriano Piattelli ◽  
...  
Keyword(s):  
Bone Resorption ◽  
Connective Tissue ◽  
Inflammatory Cell ◽  
Soft Tissues ◽  
Three Dimensional ◽  
Collagen Fibers ◽  
Inflammatory Cell Infiltration ◽  
Cell Infiltration ◽  
Oral Epithelium ◽  
Implant Abutment

Symmetric and well-organized connective tissues around the longitudinal implant axis were hypothesized to decrease early bone resorption by reducing inflammatory cell infiltration. Previous studies that referred to the connective tissue around implant and abutments were based on two-dimensional investigations; however, only advanced three-dimensional characterizations could evidence the organization of connective tissue microarchitecture in the attempt of finding new strategies to reduce inflammatory cell infiltration. We retrieved three implants with a cone morse implant–abutment connection from patients; they were investigated by high-resolution X-ray phase-contrast microtomography, cross-linking the obtained information with histologic results. We observed transverse and longitudinal orientated collagen bundles intertwining with each other. In the longitudinal planes, it was observed that the closer the fiber bundles were to the implant, the more symmetric and regular their course was. The transverse bundles of collagen fibers were observed as semicircular, intersecting in the lamina propria of the mucosa and ending in the oral epithelium. No collagen fibers were found radial to the implant surface. This intertwining three-dimensional pattern seems to favor the stabilization of the soft tissues around the implants, preventing inflammatory cell apical migration and, consequently, preventing bone resorption and implant failure. This fact, according to the authors’ best knowledge, has never been reported in the literature and might be due to the physical forces acting on fibroblasts and on the collagen produced by the fibroblasts themselves, in areas close to the implant and to the symmetric geometry of the implant itself.

scholarly journals Relationships of Stresses on Alveolar Bone and Abutment of Dental Implant from Various Bite Forces by Three-Dimensional Finite Element Analysis

2020 ◽  
Vol 2020 ◽  
pp. 1-9 ◽  
Author(s):  
Xiaoning Kang ◽  
Yiming Li ◽  
Yixi Wang ◽  
Yao Zhang ◽  
Dongsheng Yu ◽  
...  
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Dental Implant ◽  
Alveolar Bone ◽  
Three Dimensional ◽  
Central Incisor ◽  
Element Analysis ◽  
Implant Abutment ◽  
Dimensional Finite Element ◽  
Three Dimensional Finite Element

Occlusal trauma caused by improper bite forces owing to the lack of periodontal membrane may lead to bone resorption, which is still a problem for the success of dental implant. In our study, to avoid occlusal trauma, we put forward a hypothesis that a microelectromechanical system (MEMS) pressure sensor is settled on an implant abutment to track stress on the abutment and predict the stress on alveolar bone for controlling bite forces in real time. Loading forces of different magnitudes (0 N–100 N) and angles (0–90°) were applied to the crown of the dental implant of the left central incisor in a maxillary model. The stress distribution on the abutment and alveolar bone were analyzed using a three-dimensional finite element analysis (3D FEA). Then, the quantitative relation between them was derived using Origin 2017 software. The results show that the relation between the loading forces and the stresses on the alveolar bone and abutment could be described as 3D surface equations associated with the sine function. The appropriate range of stress on the implant abutment is 1.5 MPa–8.66 MPa, and the acceptable loading force range on the dental implant of the left maxillary central incisor is approximately 6 N–86 N. These results could be used as a reference for the layout of MEMS pressure sensors to maintain alveolar bone dynamic remodeling balance.

Computer Aided Modeling and Finite Element Analysis of Human Elbow

2016 ◽  
Vol 5 (1) ◽  
pp. 31-38
Author(s):  
Arpan Gupta ◽  
O.P. Singh
Keyword(s):  
Finite Element ◽  
Research Work ◽  
Well Being ◽  
Computer Aided Engineering ◽  
Weight Lifting ◽  
Patient Specific ◽  
Element Analysis ◽  
Detailed Model ◽  
Computer Aided ◽  
Safe Load

Finite element modeling (FEM) plays a significant role in the design of various devices in the engineering field of automotive, aerospace, defense etc. In the recent past, FEM is assisting engineers and healthcare professional in analyzing and designing various medical devices with advanced functionality. Computer aided engineering can predict failure circumstances, which can be avoided for the health and well-being of people. In this research work, computer aided engineering analysis of human elbow is presented beginning with modeling of human elbow from medical image data, and predicting the stresses in elbow during carrying heavy loads. The analysis is performed by using finite element method. The results predict the stress level and displacement in the human bone during heavy weight lifting. Thus, it can be used to predict the safe load that a particular person can carry without bone injury. The present analysis focused on a particular model of bone for a particular individual. However, safe load can be determined for various age groups by generating more detailed model including tendons, ligaments and by using patient specific material properties.

Histological considerations of the cleavage plane for preservation of facial and cochlear nerve functions in vestibular schwannoma surgery

2009 ◽  
Vol 110 (4) ◽  
pp. 648-655 ◽  
Author(s):  
Tomio Sasaki ◽  
Tadahisa Shono ◽  
Kimiaki Hashiguchi ◽  
Fumiaki Yoshida ◽  
Satoshi O. Suzuki
Keyword(s):  
Connective Tissue ◽  
Basic Protein ◽  
Cleavage Plane ◽  
Nerve Fibers ◽  
Vestibular Nerve ◽  
Cochlear Nerve ◽  
Tissue Layer ◽  
Connective Tissue Layer ◽  
Tumor Capsule ◽  
Tumor Parenchyma

Object The authors analyzed the tumor capsule and the tumor–nerve interface in vestibular schwannomas (VSs) to define the ideal cleavage plane for maximal tumor removal with preservation of facial and cochlear nerve functions. Methods Surgical specimens from 21 unilateral VSs were studied using classical H & E, Masson trichrome, and immunohistochemical staining against myelin basic protein. Results The authors observed a continuous thin connective tissue layer enveloping the surfaces of the tumors. Some nerve fibers, which were immunopositive to myelin basic protein and considered to be remnants of vestibular nerve fibers, were also identified widely beneath the connective tissue layer. These findings indicated that the socalled “tumor capsule” in VSs is the residual vestibular nerve tissue itself, consisting of the perineurium and underlying nerve fibers. There was no structure bordering the tumor parenchyma and the vestibular nerve fibers. In specimens of tumors removed en bloc with the cochlear nerves, the authors found that the connective tissue layer, corresponding to the perineurium of the cochlear nerve, clearly bordered the nerve fibers and tumor tissue. Conclusions Based on these histological observations, complete tumor resection can be achieved by removal of both tumor parenchyma and tumor capsule when a clear border between the tumor capsule and facial or cochlear nerve fibers can be identified intraoperatively. Conversely, when a severe adhesion between the tumor and facial or cochlear nerve fibers is observed, dissection of the vestibular nerve–tumor interface (the subcapsular or subperineurial dissection) is recommended for preservation of the functions of these cranial nerves.

Quantitative Ultrasound Imaging of Healthy and Reconstructed Cleft Lip: A Feasibility Study

2007 ◽  
Vol 44 (3) ◽  
pp. 261-268 ◽  
Author(s):  
Nancy J. M. van Hees ◽  
Johan M. Thijssen ◽  
Rinske W. Huyskens ◽  
Gert Weijers ◽  
Maartje M. Nillesen ◽  
...  
Keyword(s):  
Connective Tissue ◽  
Cleft Lip ◽  
Scar Tissue ◽  
Noninvasive Evaluation ◽  
Central Position ◽  
Tissue Layer ◽  
Loose Connective Tissue ◽  
Connective Tissue Layer ◽  
Array Transducer ◽  
Orbicularis Oris Muscle

Objective: To investigate the feasibility of echographic imaging of healthy and reconstructed cleft lip and to estimate tissue dimensions and normalized echo level. Methods: Echographic images of the upper lip were made on three healthy subjects and two patients using a linear array transducer (7 to 11 MHz bandwidth) and a noncontact gel coupling. Tissue dimensions were measured using calipers. Echo levels were calibrated and were corrected for beam characteristics, gel path, and tissue attenuation using a tissue-mimicking phantom. Results: At the central position of the philtrum, mean thickness (SD) of lip loose connective tissue layer, orbicularis oris muscle, and dense connective layer was 4.0 (0.1) mm, 2.3 (0.7) mm, and 2.2 (0.7) mm, respectively, in healthy lip at rest; and 4.1 (0.9) mm, 3.8 (1.7) mm, and 2.6 (0.6) mm, respectively, in contracted lip. Mean (SD) echo level of muscle and dense connective tissue layer with respect to echo level of lip loose connective tissue layer was −19.3 (0.6) dB and −10.7 (4.0) dB, respectively, in relaxed condition and −20.7 (1.5) dB and −7.7 (2.3) dB, respectively, in contracted state. Color mode echo images were calculated, showing lip tissues in separate colors and highlighting details like discontinuity of the orbicularis oris muscle and presence of scar tissue. Conclusions: Quantitative assessment of thickness and echo level of various lip tissues is feasible after proper echographic equipment calibration. Diagnostic potentials of this method for noninvasive evaluation of cleft lip reconstruction outcome are promising.

513 Defect Evaluation for Concrete Structures using Impact Testing : Numerical Study by Finite Element Analysis

2016 ◽  
Vol 2016.53 (0) ◽  
pp. _513-1_-_513-5_
Author(s):  
Hiroaki MATSUMOTO ◽  
Fumiyasu KURATANI ◽  
Tatsuya YOSHIDA ◽  
Masato ISO ◽  
Shigenori MOURI ◽  
...  
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Numerical Study ◽  
Concrete Structures ◽  
Impact Testing ◽  
Element Analysis

A histological and histochemical study of the development of the amnioallantois in the chick, Gallus domesticus

1970 ◽  
Vol 48 (5) ◽  
pp. 1079-1086 ◽  
Author(s):  
T. P. Kenny ◽  
M. A. Gibson
Keyword(s):  
Connective Tissue ◽  
Incubation Period ◽  
Histochemical Study ◽  
Secretory Granules ◽  
Lymphatic Vessels ◽  
Muscle Layer ◽  
Peak Activity ◽  
Tissue Layer ◽  
Connective Tissue Layer ◽  
Period 2

The amnioallantoic membrane is composed of four layers. (1) An inner amnionic epithelium which is a stratified layer during most of the incubation period. This layer stains positively for glycogen, ribonucleic acid, and neutral and acidic lipids and appears to be most active during the 15 to 17 days of incubation period. (2) A muscle layer composed of dorsoventrally and anteroposteriorly directed bands. During the early incubation stages these bands are organized to form the muscle configurations known as "cross-figures." During the later incubation stages, the organization of these muscle layers is disrupted by invasions of connective tissue and fat. (3) A connective tissue layer which includes blood and lymphatic vessels. (4) An outer allantoic epithelium which is rich in secretory granules. These granules include a sulfated mucopolysaccharide component. The activity of the allantoic epithelium increases progressively during the incubation period and is at peak activity at the 17- to 19-day incubation stage. During the final stages of incubation all layers show signs of decreased activity and degeneration.

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