scholarly journals How many implants are needed for mandibular full-arch rehabilitation?

2020 ◽  
Vol 19 ◽  
pp. e209191
Author(s):  
Karina Giovanetti ◽  
Ricardo Armini Caldas ◽  
Paulo Henrique Ferreira Caria
Keyword(s):  
Bone Tissue ◽  
Principal Stress ◽  
Three Dimensional ◽  
Maximum Principal Stress ◽  
Von Mises Stress ◽  
Principal Stresses ◽  
Dimensional Finite Element ◽  
The Difference ◽  
Von Mises ◽  
Three Dimensional Finite Element

Aim: To analyze the stress distribution at the peri-implant bone tissue of mandible in full-arch implant-supported rehabilitation using a different number of implants as support. Methods: Three-dimensional finite element models of full-arch prosthesis with 3, 4 and 5 implants and those respective mandibular bone, screws and structure were built. ANSYS Workbench software was used to analyze the maximum and minimum principal stresses (quantitative analysis) and modified von Mises stress (qualitative analysis) in peri-implant bone tissue after vertical and oblique forces (100N) applied to the structure at the cantilever site (region of the first molars). Results: The peak of tensile stress values were at the bone tissue around to the distal implant in all models. The model with 3 implants presented the maximum principal stress, in the surrounding bone tissue, higher (~14%) than the other models. The difference of maximum principal stress for model with 4 and 5 implants was not relevant (~1%). The first medial implant of the model with 5 implants presented the lower (17%) stress values in bone than model with 3 implants. It was also not different from model with 4 implants. Conclusion: Three regular implants might present a slight higher chance of failure than rehabilitations with four or five implants. The use of four implants showed to be an adequate alternative to the use of classical five implants.

A comparative study between zirconia and titanium abutments on the stress distribution in parafunctional loading: A 3D finite element analysis

2020 ◽  
Vol 28 (6) ◽  
pp. 603-613 ◽  
Author(s):  
Efe Can Sivrikaya ◽  
Mehmet Sami Guler ◽  
Muhammed Latif Bekci
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Three Dimensional ◽  
Von Mises Stress ◽  
Principal Stresses ◽  
Element Analysis ◽  
Dimensional Finite Element ◽  
3D Fea ◽  
Von Mises ◽  
Three Dimensional Finite Element

BACKGROUND: Zirconia has become a popular biomaterial in dental implant systems because of its biocompatible and aesthetic properties. However, this material is more fragile than titanium so its use is limited. OBJECTIVES: The aim of this study was to compare the stresses on morse taper implant systems under parafunctional loading in different abutment materials using three-dimensional finite element analysis (3D FEA). METHODS: Four different variations were modelled. The models were created according to abutment materials (zirconia or titanium) and loading (1000 MPa vertical or oblique on abutments). The placement of the implants (diameter, 5.0 × 15 mm) were mandibular right first molar. RESULTS: In zirconia abutment models, von Mises stress (VMS) values of implants and abutments were decreased. Maximum and minimum principal stresses and VMS values increased in oblique loading. VMS values were highest in the connection level of the conical abutments in all models. CONCLUSIONS: Using conical zirconia abutments decreases von Mises stress values in abutments and implants. However, these values may exceed the pathological limits in bruxism patients. Therefore, microfractures may be related to the level of the abutment.

scholarly journals A 3-D Finite Element Study of the Influence of Crown-Implant Ratio on Stress Distribution

2013 ◽  
Vol 24 (6) ◽  
pp. 635-641 ◽  
Author(s):  
Sandra Lucia Dantas de Moraes ◽  
Fellippo Ramos Verri ◽  
Joel Ferreira Santiago Junior ◽  
Daniel Augusto de Faria Almeida ◽  
Caroline Cantieri de Mello ◽  
...  
Keyword(s):  
Finite Element ◽  
Bone Tissue ◽  
Three Dimensional ◽  
Maximum Principal Stress ◽  
Von Mises Stress ◽  
Bone Block ◽  
Crown Height ◽  
Oblique Loading ◽  
Von Mises ◽  
Three Dimensional Finite Element

The purpose of this study was to assess the influence of the crown height of external hexagon implants on the displacement and distribution of stress to the implant/bone system, using the three-dimensional finite element method. The InVesalius and Rhinoceros 4.0 softwares were used to generate the bone model by computed tomography. Each model was composed of a bone block with one implant (3.75x10.0 mm) with external hexagon connections and crowns with 10 mm, 12.5 mm and 15 mm in height. A 200 N axial and a 100 N oblique (45°) load were applied. The models were solved by the NeiNastran 9.0 and Femap 10.0 softwares to obtain the results that were visualized by maps of displacement, von Mises stress (crown/implant) and maximum principal stress (bone). The crown height under axial load did not influence the stress displacement and concentration, while the oblique loading increased these factors. The highest stress was observed in the neck of the implant screw on the side opposite to the loading. This stress was also transferred to the crown/platform/bone interface. The results of this study suggest that the increase in crown height enhanced stress concentration at the implant/bone tissue and increased displacement in the bone tissue, mainly under oblique loading.

scholarly journals Evaluation of Stresses on Implant, Bone, and Restorative Materials Caused by Different Opposing Arch Materials in Hybrid Prosthetic Restorations Using the All-on-4 Technique

Materials ◽  
2021 ◽  
Vol 14 (15) ◽  
pp. 4308
Author(s):  
Feras Haroun ◽  
Oguz Ozan
Keyword(s):  
Three Dimensional ◽  
Von Mises Stress ◽  
Prosthetic Material ◽  
Principal Stresses ◽  
Element Analysis ◽  
Minimum Principal Stress ◽  
Dimensional Finite Element ◽  
Hybrid Prosthesis ◽  
Von Mises ◽  
Three Dimensional Finite Element

The long-term success of dental implants is greatly influenced by the use of appropriate materials while applying the “All-on-4” concept in the edentulous jaw. This study aims to evaluate the stress distribution in the “All-on-4” prosthesis across different material combinations using three-dimensional finite element analysis (FEA) and to evaluate which opposing arch material has destructive effects on which prosthetic material while offering certain recommendations to clinicians accordingly. Acrylic and ceramic-based hybrid prosthesis have been modelled on a rehabilitated maxilla using the “All-on-4” protocol. Using different materials and different supports in the opposing arch (natural tooth, and implant/ceramic, and acrylic), a multi-vectorial load has been applied. To measure stresses in bone, maximum and minimum principal stress values were calculated, while Von Mises stress values were obtained for prosthetic materials. Within a single group, the use of an acrylic implant-supported prosthesis as an antagonist to a full arch implant-supported prosthesis yielded lower maximum (Pmax) and minimum (Pmin) principal stresses in cortical bone. Between different groups, maxillary prosthesis with polyetheretherketone as framework material showed the lowest stress values among other maxillary prostheses. The use of rigid materials with higher moduli of elasticity may transfer higher stresses to the peri implant bone. Thus, the use of more flexible materials such as acrylic and polyetheretherketone could result in lower stresses, especially upon atrophic bones.

scholarly journals A three - dimensional finite element study on the stress distribution pattern of two prosthetic abutments for external hexagon implants

2013 ◽  
Vol 07 (04) ◽  
pp. 484-491 ◽  
Author(s):  
Wagner Moreira ◽  
Caio Hermann ◽  
Jucélio Tomás Pereira ◽  
Jean Anacleto Balbinoti ◽  
Rodrigo Tiossi
Keyword(s):  
Finite Element ◽  
Stress Distribution ◽  
Three Dimensional ◽  
Von Mises Stress ◽  
Element Analysis ◽  
Dimensional Finite Element ◽  
3D Fea ◽  
The One ◽  
Von Mises ◽  
Three Dimensional Finite Element

ABSTRACT Objective: The purpose of this study was to evaluate the mechanical behavior of two different straight prosthetic abutments (one- and two-piece) for external hex butt-joint connection implants using three-dimensional finite element analysis (3D-FEA). Materials and Methods: Two 3D-FEA models were designed, one for the two-piece prosthetic abutment (2 mm in height, two-piece mini-conical abutment, Neodent) and another one for the one-piece abutment (2 mm in height, Slim Fit one-piece mini-conical abutment, Neodent), with their corresponding screws and implants (Titamax Ti, 3.75 diameter by 13 mm in length, Neodent). The model simulated the single restoration of a lower premolar using data from a computerized tomography of a mandible. The preload (20 N) after torque application for installation of the abutment and an occlusal loading were simulated. The occlusal load was simulated using average physiological bite force and direction (114.6 N in the axial direction, 17.1 N in the lingual direction and 23.4 N toward the mesial at an angle of 75° to the occlusal plan). Results: The regions with the highest von Mises stress results were at the bottom of the initial two threads of both prosthetic abutments that were tested. The one-piece prosthetic abutment presented a more homogeneous behavior of stress distribution when compared with the two-piece abutment. Conclusions: Under the simulated chewing loads, the von Mises stresses for both tested prosthetic-abutments were within the tensile strength values of the materials analyzed which thus supports the clinical use of both prosthetic abutments.

Optimization of Adhesively Bonded Spar-Wingskin Joints of Laminated FRP Composites Subjected to Pull-Off Load: A Critical Review

2020 ◽  
Vol 8 (1) ◽  
pp. 29-46
Author(s):  
S. Rakshe ◽  
S. V. Nimje ◽  
S. K. Panigrahi
Keyword(s):  
Three Dimensional ◽  
Von Mises Stress ◽  
Geometrical Parameters ◽  
Adhesively Bonded ◽  
Element Analysis ◽  
Frp Composites ◽  
Dimensional Finite Element ◽  
Materials Used ◽  
Von Mises ◽  
Three Dimensional Finite Element

A review on optimization of adhesively bonded spar-wingskin joint (SWJ) of laminated fiber reinforced polymer (FRP) composites subjected to pull-off load is presented in this article using three-dimensional finite element analysis. Von Mises stress components have been computed across the width of joint at different interfaces viz. load coupler-spar, and load coupler-wingskin interfaces. Further, the weight of SWJ structure is considered as the objective function which needs to be minimized for optimization. In the first step, the material and lamination scheme of the FRP composite materials used for SWJ are optimized, and, in the second step, the geometrical parameters have been optimized on the basis of minimum von Mises stress and weight. Further, the effects of the material, lamination scheme, and geometrical parameters on the von Mises stress and weight have been validated using the Analysis of Variance (ANOVA) approach as prescribed by the Taguchi method. The results show that the material and spar thickness are the most significant factors influencing von Mises stress. The weight analysis reveals that there is a significant effect of change in material and wingskin thickness on SWJ performance. Suitable design recommendations have been made for SWJ in terms of material, lamination scheme and geometrical parameters.

scholarly journals Effect of Maxillary Implants Region and Loading Condition in the Stress Distribution of Implant-Supported Full-Arch Prosthesis: 3D-FEA

2021 ◽  
Author(s):  
Mateus Favero Barra Grande ◽  
Marcelo Lucchesi Teixeira ◽  
André Antônio Pelegrine ◽  
Guilherme Da Rocha Scalzer Lopes ◽  
Julio Ferraz Campos ◽  
...  
Keyword(s):  
Finite Element ◽  
Dental Implants ◽  
Dental Treatment ◽  
Three Dimensional ◽  
Von Mises Stress ◽  
Cobalt Chromium ◽  
Element Analysis ◽  
Dimensional Finite Element ◽  
Von Mises ◽  
Three Dimensional Finite Element

The effect of the different dental implants positioning region on the stress performance of the implant-supported prosthesis is not yet clear. This study evaluated the dental treatment with six dental implants in three different models and three different occlusal loading conditions, in terms of the biomechanical response of implants, prosthetic screw and maxilla, using three-dimensional finite element analysis. The finite element models were modelled containing external hexagon implants, as well as a Cobalt-Chromium superstructure. Three types of loads were applied: in the area of ​​the central incisors, first premolar and in the second molars. For the finite element simulations, the von-Mises stress peaks in the implant and in the surrounding cortical bone were analyzed. All recorded results reported higher values ​​for the implant-supported prosthesis in group C compared to the groups A and B. The highest stress values, ​​regardless the evaluated model, was in the prosthesis in group C and in screws, the smallest were in group A.

Simplified Numerical Model for Rapid Design of AF Module Spring Shape Parameters

2017 ◽  
Vol 34 (5) ◽  
pp. 591-600
Author(s):  
D. S. Liu ◽  
C. J. Lu ◽  
S. H. Chen ◽  
C. S. Liu ◽  
T. W. Liao
Keyword(s):  
Reaction Force ◽  
Three Dimensional ◽  
Voice Coil Motor ◽  
Von Mises Stress ◽  
Structural Method ◽  
Spring Stiffness ◽  
Shape Parameters ◽  
Dimensional Finite Element ◽  
Von Mises ◽  
Three Dimensional Finite Element

AbstractThe autofocusing (AF) performance of cell phone cameras is critically dependent on the design of the voice-coil motor (VCM) used to drive the lens module. Also, the metal springs in the AF module should combine high stiffness with a good actuation response and a light weight. The present study utilizes a reverse engineering approach to construct three-dimensional finite element models of the top and bottom springs in the VCM mechanism. Simulations are then performed to investigate the von Mises stress distribution and stiffness characteristics of the two springs given horizontal and vertical orientations of the AF module, respectively. In performing the simulations, the actuation force is computed using two different analysis methods, namely a simplify structure method and a coupled electromagnetic-structural method. It is shown that the simplify structure method has the advantages of a lower computational complexity and a more comprehensive modeling capability. A further series of simulations is thus to examine the effects of the spring shape parameters on the reaction force developed by the spring stiffness. The results show that the spring stiffness increases with an increasing thickness and a decreasing rib length. The simulation results obtained for different spring shape parameter settings are summarized in the form of a parameter design chart for predicting the reaction force given known values of the spring rib length and spring thickness.

Three-Dimensional Finite Element Stress Response Analysis of Laminated Cantilever Beams With Adhesive Layers Subjected to Impact Loadings

1999 ◽  
Author(s):  
Jyo Shimura ◽  
Izumi Higuchi ◽  
Toshiyuki Sawa
Keyword(s):  
Young’S Modulus ◽  
Principal Stress ◽  
Young's Modulus ◽  
Three Dimensional ◽  
Maximum Principal Stress ◽  
Stress Wave Propagation ◽  
Adhesive Interface ◽  
Number Of Layers ◽  
Dimensional Finite Element ◽  
Three Dimensional Finite Element

Abstract The stress behavior in adhesive laminated cantilever beams subjected to impact loadings is analyzed using three-dimensional finite-element method (FEM) in the elastic region. The stress wave propagation and the stress distribution at the interfaces are examined. The effects of Young’s modulus of adherends, adhesive, the adherend thickness and the number of layers on the stress wave propagation at the interfaces are clarified. The following results are obtained. The maximum principal stress (σ1) is maximal at the adhesive interfaces. It is found that the maximum principal stress (σ1) at the adhesive interface increases as the Young’s modulus of the upper adherends increases. The maximum principal stress (σ1) at the adhesive interface increases as Young’s modulus of the adhesive increases. The maximum principal stress (σ1) at the adhesive interface decreases as the thickness of the adherend to which an impact load is applied increases. It is seen that the maximum principal stress (σ1) increases as number of layers increases. Experiments were carried out to measure the strain response of adhesive laminated cantilever beam using strain gauges. A fairly good agreement is seen between the analytical and experimental results.

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