scholarly journals Finite Element Analysis in Setting of Fillings of V-Shaped Tooth Defects Made with Glass-Ionomer Cement and Flowable Composite

Processes ◽  
2020 ◽  
Vol 8 (3) ◽  
pp. 363 ◽  
Author(s):  
Tsanka Dikova ◽  
Tihomir Vasilev ◽  
Vesela Hristova ◽  
Vladimir Panov
Keyword(s):  
Finite Element Analysis ◽  
Experimental Study ◽  
Finite Element ◽  
Glass Ionomer Cement ◽  
Adhesive Layer ◽  
Glass Ionomer ◽  
Element Analysis ◽  
Von Mises ◽  
Von Mises Stresses ◽  
Ionomer Cement

The aim of the present paper is to investigate the deformation–stress state of fillings of V-shaped tooth defects by finite element analysis (FEA). Two different materials are used—auto-cured resin-reinforced glass-ionomer cement (GIC) and flowable photo-cured composite (FPC). Two materials are placed into the cavity in one portion, as before the application of the composite the cavity walls are covered with a thin adhesive layer. Deformations and equivalent von Mises stresses are evaluated by FEA. Experimental study of micro-leakage is performed. It is established that there is an analogous non-homogeneous distribution of equivalent Von Mises stresses at fillings of V-shaped defects, made with GIC and FPC. Maximum stresses are generated along the boundaries of the filling on the vestibular surface of the tooth and at the bottom of the filling itself. Values of equivalent Von Mises stresses of GIC fillings are higher than that of FPC. Magnitude and character of deformation distribution at GIC and FPC fillings are similar—deformation is maximum along the vestibular surface of the filling and is 0.056 and 0.053 mm, respectively. In FPC fillings, the adhesive layer, located along the cavity/filling boundary, is characterized with greatest strain. The experimental study of micro-leakage has confirmed the adequacy of models used in FEA.

scholarly journals Modified Technique of Porcelain Laminate Veneer in Premolars with Abfraction Lesions: Three-Dimensional Finite Element Analysis (FEA)

2020 ◽  
Vol 22 (2) ◽  
pp. 120-126
Author(s):  
Larissa Marcia Martins Alves ◽  
Lisseth Patricia Claudio Contreras ◽  
João Paulo Mendes Tribst ◽  
Renata Marques de Melo ◽  
Alexandre Luiz Souto Borges
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Composite Resin ◽  
Glass Ionomer Cement ◽  
Three Dimensional ◽  
Glass Ionomer ◽  
Element Analysis ◽  
3D Fea ◽  
Laminate Veneers ◽  
Ionomer Cement

The incidence of non-carious cervical lesions (NCCLs) has increased as populations are aging, and teeth are increasingly retained for life. Several materials are available to treat these lesions. This study aimed to evaluate the stress distribution of maxillary premolars with NCCLs using three-dimensional (3D) finite element analysis (FEA) according to different restorative techniques. A 3D FEA mathematical model simulating a sound premolar was initially modeled and replicated in 6 more models simulating a tooth with abfraction: G.1 tooth with abfraction; G.2 tooth with abfraction + composite resin restoration; G.3 tooth with abfraction + glass-ionomer cement restoration; G.4 tooth with abfraction + resin composite restoration + porcelain laminate veneers; G.5 tooth with abfraction + glass-ionomer cement + porcelain laminate veneers; and G.6 modified porcelain laminate veneers filling the lesion. All materials and structures were considered linear, elastic, homogeneous and isotropic and the results were expressed as maximum principal stress. Lower stress concentration in dentin was calculated when the tooth was restored with composite resin and glass-ionomer cement. Regarding the veneer techniques, no difference was found to dentin stress among the groups, but the modified veneer concentrated less stress in the restoration than other the techniques. The control group had the highest concentration of stress in the lesion. All techniques decreased the stress concentration inside the NCCLs and the indirect veneer filling the lesion presented better biomechanical behavior than the veneer cemented above direct restorations.  Keywords: Finite Element Analysis. Dental Veneers. Ceramics. Bicuspid. Resumo A incidência de lesões cervicais não-cariosas (LCNC) tem aumentado, uma vez que a população tem envelhecido com uma menor perda de elementos dentários. Diferentes materiais estão disponíveis para tratar dessas lesões. Este estudo objetivou avaliar a distribuição de tensão de pré-molares superiores com LCNC por meio da análise tridimensional (3D) de elementos finitos (FEA) de acordo com diferentes técnicas restauradoras. Um modelo matemático 3D FEA simulando um pré-molar íntegro foi modelado e replicado em mais 6 modelos simulando um dente com abfração: G.1 dente com abfração; G.2 dente com abfração + resina composta; G.3 dente com abfração + cimento de ionômero de vidro; G.4 dente com abfração + resina composta + faceta; G.5 dente com abfração + cimento de ionômero de vidro + faceta cerâmica e G.6 com faceta cerâmica modificada, preenchendo a lesão. Todos os materiais e estruturas foram considerados lineares, elásticos, homogêneos e isotrópicos e os resultados foram expressos como máxima tensão principal. Menor concentração de tensão na dentina foi calculada quando o dente foi restaurado com resina composta ou cimento de ionômero de vidro. Dentre os grupos com laminados, não houve diferença para a dentina, entretanto a faceta modificada apresentou menor concentração de tensão na restauração. O grupo controle apresentou a maior concentração de tensão na lesão. Todas as técnicas restauradoras diminuíram a concentração de tensão no interior das LCNCs e dentre as técnicas com laminados a faceta modificada apresentou o melhor comportamento biomecânico. Palavras-chave: Análise de Elementos Finitos. Facetas Dentárias. Cerâmica. Dente Pré-Molar.

Experimental Study and Finite Element Analysis of the Performance of Reciprocating Seal in Rapping Device of Gasifier

2010 ◽  
Vol 42 ◽  
pp. 48-53
Author(s):  
Jiu Yang Yu ◽  
Jiu Yang Gao ◽  
Wei Lin ◽  
Cheng Gang Wang ◽  
Yan Yang Wu ◽  
...  
Keyword(s):  
Finite Element Method ◽  
Finite Element Analysis ◽  
Experimental Study ◽  
Finite Element ◽  
Contact Stress ◽  
Power Loss ◽  
Von Mises Stress ◽  
Seal Ring ◽  
Element Analysis ◽  
Von Mises

The performance of reciprocating seals in rapping device of gasifier was studied through finite element method. The contact stress, Von-Mises stress, and friction power loss of O-ring and Sliding-ring combined Seal-ring were obtained. Meanwhile, the experimental study in performance of seal structures of rapping device were carried out. The results show that both of the seal structures are satisfied seal requirement, but compared with the Sliding-ring combined Seal-ring, the O-ring is easier to be destroyed and power loss of O-ring is higher than Sliding-ring combined Seal-ring. The results also verify the superiority of Sliding-ring combined Seal-ring in rapping device of gasifier.

scholarly journals Effect of Augmentation Material Stiffness on Adjacent Vertebrae after Osteoporotic Vertebroplasty Using Finite Element Analysis with Different Loading Methods

2015 ◽  
Vol 6;18 (6;11) ◽  
pp. E1101-E1110
Author(s):  
Ah-Reum Cho
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Bone Cement ◽  
Vertebral Fractures ◽  
Three Dimensional ◽  
Element Model ◽  
Element Analysis ◽  
Adjacent Vertebral Body ◽  
Von Mises ◽  
Von Mises Stresses

Background: Vertebroplasty is an effective treatment for osteoporotic vertebral fractures, which are one of the most common fractures associated with osteoporosis. However, clinical observation has shown that the risk of adjacent vertebral body fractures may increase after vertebroplasty. The mechanism underlying adjacent vertebral body fracture after vertebroplasty is not clear; excessive stiffness resulting from polymethyl methacrylate has been suspected as an important mechanism. Objectives: The aim of our study was to compare the effects of bone cement stiffness on adjacent vertebrae after osteoporotic vertebroplasty under load-controlled versus displacementcontrolled conditions. Study Design: An experimental computer study using a finite element analysis. Setting: Medical research institute, university hospital, Korea. Methods: A three-dimensional digital anatomic model of L1/2 bone structure was reconstructed from human computed tomographic images. The reconstructed three-dimensional geometry was processed for finite element analysis such as meshing elements and applying material properties. Two boundary conditions, load-controlled and displacement-controlled methods, were applied to each of 5 deformation modes: compression, flexion, extension, lateral bending, and torsion. Results: The adjacent L1 vertebra, irrespective of augmentation, revealed nearly similar maximum von Mises stresses under the load-controlled condition. However, for the displacementcontrolled condition, the maximum von Mises stresses in the cortical bone and inferior endplate of the adjacent L1 vertebra increased significantly after cement augmentation. This increase was more significant than that with stiffer bone cement under all modes, except the torsion mode. Limitations: The finite element model was simplified, excluding muscular forces and incorporating a large volume of bone cement, to more clearly demonstrate effects of bone cement stiffness on adjacent vertebrae after vertebroplasty. Conclusion: Excessive stiffness of augmented bone cement increases the risk of adjacent vertebral fractures after vertebroplasty in an osteoporotic finite element model. This result was most prominently observed using the displacement-controlled method. Key words: Bone cements, displacement-controlled method, finite element analysis, loadcontrolled method, osteoporosis, osteoporotic fracture, polymethyl methacrylate, vertebroplasty

scholarly journals Assessing the Impact of Changes on Design and Material of Howe Bridges by Finite Element Analysis

2021 ◽  
Vol 3 (3) ◽  
pp. 33-37
Author(s):  
Jairo Aparecido Martins ◽  
Estaner Claro Romão
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Lateral Loads ◽  
Element Analysis ◽  
Design Changes ◽  
Minimal Design ◽  
Von Mises ◽  
Truss Bridge ◽  
Von Mises Stresses ◽  
The Impact

This paper presents an investigation of changes on design and material of a Howe bridge under vertical loads. Specifically, it aimed to find out how small changes on Howe bridge design and material affected von Mises stresses as well as stresses at Z direction. As a method, it was used a finite element analysis (linear-elastic) by Autodesk F-360. Half of a bridge was designed (one bridge side) and loaded with a central higher load and two equal smaller lateral loads. In essence, von Mises stresses (s) and stress at Z direction (sz) decreased on stresses values until a certain design change, which was proportional to a raise of mass due to beams added on the trusses. With a change of material to a lighter metal, from steel to aluminum, it was possible to overcome the mass drawback brought by steel and utterly possible to end up for a more effective design for a Howe truss bridge by applying minimal design changes.

scholarly journals Stress distribution in a mandibular premolar after separated nickel-titanium instrument removal and root canal preparation: a three-dimensional finite element analysis

2019 ◽  
Vol 47 (4) ◽  
pp. 1555-1564 ◽  
Author(s):  
Na Ni ◽  
Jing Ye ◽  
Liyuan Wang ◽  
Simin Shen ◽  
Lei Han ◽  
...  
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Stress Distribution ◽  
Three Dimensional ◽  
Cervical Region ◽  
Element Analysis ◽  
Straight Line ◽  
Mandibular First Premolar ◽  
Von Mises ◽  
Von Mises Stresses

Objective This study used finite element analysis (FEA) to assess the von Mises stresses of a mandibular first premolar after removing a separated instrument with an ultrasonic technique. Methods FEA models of the original and treated mandibular first premolar were reconstructed, and three models (the original canal, size 30/taper 0.04 canal, and separated instrument removal canal) were created. Two-direction (vertical and lateral) loading patterns were simulated with a 175-N force. The maximum von Mises stresses of the models within the roots from the apex to the cervical region were collected and summarized. Results Under vertical and lateral loads, all maximal values in the three models were localized in the straight-line access region. Compared with the original model (model 1), the treated models (models 2 and 3) had greater maximum stress values from the apex to the cervical region. Greater differences in the maximum von Mises stresses between models 2 and 3 were present in the straight-line access region. Conclusions Separated instrument removal caused changes in stress distribution and increases in stress concentration in the straight-line access region of roots.

scholarly journals Influence of sagittal root positions on the stress distribution around custom-made root-analogue implants: a three-dimensional finite element analysis

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Chunping Lin ◽  
Hongcheng Hu ◽  
Junxin Zhu ◽  
Yuwei Wu ◽  
Qiguo Rong ◽  
...  
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Stress Concentration ◽  
Class I ◽  
Von Mises Stress ◽  
Element Analysis ◽  
Custom Made ◽  
Root Position ◽  
Von Mises ◽  
Von Mises Stresses

Abstract Background Stress concentration may cause bone resorption even lead to the failure of implantation. This study was designed to investigate whether a certain sagittal root position could cause stress concentration around maxillary anterior custom-made root-analogue implants via three-dimensional finite element analysis. Methods The von Mises stresses in the bone around implants in different groups were compared by finite element analysis. Six models were constructed and divided into two groups through Geomagic Studio 2012 software. The smooth group included models of unthreaded custom-made implants in Class I, II or III sagittal root positions. The threaded group included models of reverse buttress-threaded implants in the three positions. The von Mises stress distributions and the range of the stresses under vertical and oblique loads of 100 N were analyzed through ANSYS 16.0 software. Results Stress concentrations around the labial lamella area were more prominent in the Class I position than in the Class II and Class III positions under oblique loading. Under vertical loading, the most obvious stress concentration areas were the labial lamella and palatal apical areas in the Class I and Class III positions, respectively. Stress was relatively distributed in the labial and palatal lamellae in the Class II position. The maximum von Mises stresses in the bone around the custom-made root-analogue implants in this study were lower than around traditional implants reported in the literature. The maximum von Mises stresses in this study were all less than 25 MPa in cortical bone and less than 6 MPa in cancellous bone. Additionally, compared to the smooth group, the threaded group showed lower von Mises stress concentration in the bone around the implants. Conclusions The sagittal root position affected the von Mises stress distribution around custom-made root-analogue implants. There was no certain sagittal root position that could cause excessive stress concentration around the custom-made root-analogue implants. Among the three sagittal root positions, the Class II position would be the most appropriate site for custom-made root-analogue implants.

scholarly journals FINITE ELEMENT ANALYSIS USING SHELL ELEMENTS ON RETICULATED STRUCTURES

2017 ◽  
Vol 2 (2) ◽  
Author(s):  
Alexandre Huberto Balbino Selhorst ◽  
Rafael Elias Meyer ◽  
Tatielen Pereira Costa ◽  
Liércio André Isoldi
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Von Mises Stress ◽  
The Finite Element Method ◽  
Element Analysis ◽  
Shell Elements ◽  
Final Weight ◽  
Verification Process ◽  
Von Mises ◽  
Von Mises Stresses

This paper studies the possibility of using SHELL elements on structures that are usually designed using BEAM or BAR elements. Using SHELL elements in such structures, named reticulated structures, opens the possibility to remove material from the structures’ members by adding holes. Once the members get holes, the final weight of the structure and material consumption will drop. In order to develop the study, a total of three different structures were analyzed using the software ANSYS®. This software uses the Finite Element Method to solve the equations originated from the designed structure upon it is meshed and the boundary conditions are set. Several results between SHELL and SOLID elements for each one of the structures were compared. The comparison of SHELL model with a SOLID model is used as a verification process, for SOLID elements are known to return accurate values. All of the meshes were tested by the independence mesh study to check its convergence. It is shown that the results are in a very good acceptable range with differences no bigger than 0.1 mm for displacements, and the map of von Mises stresses are pretty similar. Von Mises stresses for Finite Element Analysis for the C-Shaped Truss are shown in a figure comparing the results between the two finite elements used. This figure shows that there are no major differences between the SHELL and SOLID analyses. The Finite Element Analyses results were compared to analytical solutions, also. In this case, a noticeable difference in one structure for von Mises Stress was found. This difference, however, is understandable and reasonable, given the works presented on this paper.

scholarly journals Finite Element Analysis Comparison of Plate Designs in Managing Fractures Involving the Mental Foramen

2013 ◽  
Vol 6 (2) ◽  
pp. 93-97 ◽  
Author(s):  
Neralla Mahathi ◽  
Emmanuel Azariah ◽  
C. Ravindran
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Three Dimensional ◽  
Mental Foramen ◽  
Stress Generation ◽  
Von Mises Stress ◽  
Element Analysis ◽  
Plate Design ◽  
Von Mises ◽  
Von Mises Stresses

Introduction The aim of the study was to propose an ideal plating design for fractures running through the mental foramen. Methods The study compared three plating designs—two four-hole miniplates, 2 × 2-hole three-dimensional (3D) plate, and modified 2 × 2-hole 3D plate (posterior strut removed)—using finite element analysis. Von Mises stresses generated around the plates and bone were measured, as well as the mobility that is generated between the fracture fragments by applying muscle forces to generate bite force in one test and applying a force of 500 N over the premolars and first molar region in the second test. Results Von Mises stress in bone with miniplates measured 9.24 MPa in test 1 and 131.99 MPa in test 2. The stress with unmodified 3D plates measured 34.9 MPa in test 1 and150.03 MPa in test 2. The stress with modified 3D plates measured 24.98 MPa in test 1 and 150.59 MPa in test 2. Von Mises stress on the plates and screws measured 28.23 MPa, 95.97 MPa, 72.93 MPa in test 1 and 458.63 MPa, 779.01 MPa, 742.39 MPa in test 2 on miniplates, unmodified 3D plates, and modified 3D plates, respectively. The fracture mobility generated in the model with miniplates measured 0.001 mm in test 1 and 0.01 mm in test 2 and 0.007 mm and 0.02 mm in the model with unmodified 3D plates in test 1 and in test 2, respectively. In the model with modified 3D plates, the value was 0.001 mm and 0.01 mm in tests 1 and 2, respectively. Conclusion The ideal plate design is the two-plate technique with minimal stress generation on the bone and the hardware. The modified 3D plate has adequate strength to be used in the region but needs to be studied in detail.

scholarly journals Comparison of stresses in monoblock tilted implants and conventional angled multiunit abutment-implant connection systems in the all-on-four procedure

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Özge Özdal Zincir ◽  
Ateş Parlar
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Surgical Procedures ◽  
Principal Stresses ◽  
Element Analysis ◽  
Edentulous Mandible ◽  
Group A ◽  
Group B ◽  
Von Mises ◽  
Von Mises Stresses

Abstract Background The All-on-four dental implant method is an implantology method designed to provide a comfortable prosthetic treatment option by avoiding advanced surgical procedures. This research aims to compare and evaluate the stress and tension values in conventional angled multiunit abutment-implant connection systems and monoblock dental implants used in the all-on-four procedure with finite element analysis. Methods Two master models were created by placing four implants connected to multiunit abutments (group A) in the interforaminal region of a completely edentulous mandible and four monoblock implants (group B) in the same region of another completely edentulous mandible. Group A implants were classified according to their diameter as follows: 3.5 mm (M1A), 4.0 mm (M2A), and 4.5 mm (M3A). Similarly, group B implants were classified as M1B, M2B, and M3B. In the six models rehabilitated with acrylic fixed prostheses, a 100 N force was applied to the anterior implant region, and a 250 N force was applied to the posterior cantilever in both axial and 30° oblique directions. Von Mises stresses were analyzed in the bone and implant regions of all models. Results M1A and M1B, M2A and M2B, and M3A and M3B were compared with each other under axial and oblique forces. The maximum Von Mises stresses in the bone around implants and the prosthesis screws, and the maximum and minimum principal stresses in the cortical and trabecular bone in group A models were significantly higher than those in group B models. Conclusions In monoblock implant systems under axial and oblique forces, higher stress is accumulated in the bone, prosthesis screw and implant compared to multiunit abutment-implant connection systems.

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