scholarly journals Implant Inclination and Horizontal Misfit in Metallic Bar Framework of Overdentures: Analysis By 3D-FEA Method

2018 ◽  
Vol 29 (2) ◽  
pp. 166-172 ◽  
Author(s):  
Ricardo Armini Caldas ◽  
Carmem Silvia Costa Pfeifer ◽  
Ataís Bacchi ◽  
Mateus Bertolini Fernandes dos Santos ◽  
Vagner Flávio Reginato ◽  
...  
Keyword(s):  
Bone Tissue ◽  
Cross Sections ◽  
Alveolar Bone ◽  
Three Dimensional ◽  
Element Analysis ◽  
3D Fea ◽  
Negative Effect ◽  
Von Mises ◽  
The Right ◽  
Three Dimensional Finite Element

Abstract The aim of this study was to evaluate by three-dimensional finite element analysis (3D-FEA) the biomechanics involved in bar-framework system for overdentures. The studied factors were latero-lateral angulation in the right implant (-10, -5, 0, 5 and 10 degrees), and different bar cross-sections (circular, Hader and oval) presenting horizontal misfits (50 or 150 µm) on the opposite implant. Positive angulation (5 and 10 degrees) for implant inclination to mesial position, negative angulation (-5 and -10 degrees) for distal position, and zero degree for parallel implants. The von Mises stresses evaluated the bar, screw and the implant; maximum principal, minimum principal and shear stress analyses evaluated the peri-implant bone tissue. Parallel implants provide lower stress in alveolar bone tissue; mesial inclined bars showed the most negative effect on prosthetic structures and implants. In conclusion, bar cross-section showed no influence on stress distribution for peri-implant bone tissue, and circular bar provided better behavior to the prosthetic system. Higher stress concentration is provided to all system as the misfit increases.

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 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.

scholarly journals Biomechanical Analysis of the Canine Tuberculum Dentale

2018 ◽  
Vol 18 (2) ◽  
pp. 50-54
Author(s):  
Ionut Ichim ◽  
Michael Swain ◽  
Jules Kieser
Keyword(s):  
Alveolar Bone ◽  
Three Dimensional ◽  
Biomechanical Analysis ◽  
Element Analysis ◽  
Occlusal Force ◽  
Dimensional Finite Element ◽  
Von Mises ◽  
Three Dimensional Finite Element ◽  
Von Mises Stresses ◽  
Structural Significance

We evaluate the structural significance of the development of a canine tuberculum dentale by means of three-dimensional finite element analysis. Using a scanned human permanent canine, we construct a computer generated canine, together with alveolar bone and periodontal ligament onto which we morph two cingulum shapes, namely a flat palatal surface and a stylised tuberculum dentale. We then subject the three shapes (flat, normal cingulum, and pronounced tuberculum dentale) to a normal occlusal force and we record principal and von Mises stresses in the crowns. Our results show that stresses are concentrated at the cingulum and in the approximal areas, and that these do not differ between the three forms. We conclude that the development of a tuberculum dentale does not confer biomechanical advantage to the human canine.

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.

scholarly journals A finite element analysis of sacroiliac joint displacements and ligament strains in response to three manipulations

2020 ◽  
Vol 21 (1) ◽  
Author(s):  
Zhun Xu ◽  
Yikai Li ◽  
Shaoqun Zhang ◽  
Liqing Liao ◽  
Kai Wu ◽  
...  
Keyword(s):  
Finite Element ◽  
Sacroiliac Joint ◽  
Clinical Effect ◽  
Three Dimensional ◽  
Element Model ◽  
Element Analysis ◽  
Ligament Strain ◽  
Dimensional Finite Element ◽  
The Right ◽  
Three Dimensional Finite Element

Abstract Background Clinical studies have found that manipulations have a good clinical effect on sacroiliac joint (SIJ) pain without specific causes. However, the specific mechanisms underlying the effect of manipulations are still unclear. The purpose of this study was to investigate the effects of three common manipulations on the stresses and displacements of the normal SIJ and the strains of the surrounding ligaments. Methods A three-dimensional finite element model of the pelvis-femur was developed. The manipulations of hip and knee flexion (MHKF), oblique pulling (MOP), and lower limb hyperextension (MLLH) were simulated. The stresses and displacements of the SIJ and the strains of the surrounding ligaments were analyzed during the three manipulations. Results MOP produced the highest stress on the left SIJ, at 6.6 MPa, while MHKF produced the lowest stress on the right SIJ, at 1.5 MPa. The displacements of the SIJ were all less than 1 mm during the three manipulations. The three manipulations caused different degrees of ligament strain around the SIJ, and MOP produced the greatest straining of the ligaments. Conclusion The three manipulations all produced small displacements of the SIJ and different degrees of ligament strains, which might be the mechanism through which they relieve SIJ pain. MOP produced the largest displacement and the greatest ligament strains.

Parametric study on the capability of three-dimensional finite element analysis (3D-FEA) of compressive behaviour of Douglas fir

Holzforschung ◽  
2016 ◽  
Vol 70 (6) ◽  
pp. 539-546 ◽  
Author(s):  
Jung-Pyo Hong ◽  
Jun-Jae Lee ◽  
Hwanmyeong Yeo ◽  
Chul-Ki Kim ◽  
Sung-Jun Pang ◽  
...  
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Three Dimensional ◽  
Douglas Fir ◽  
Element Analysis ◽  
Compressive Behaviour ◽  
Wood Compression ◽  
Dimensional Finite Element ◽  
3D Fea ◽  
Three Dimensional Finite Element

Abstract This study is aiming at the simulation of wood compression (C) at a macroscopic level by means of a three-dimensional finite element analysis (3D-FEA) of solid wood and evaluation of the capability and limitations of this approach. C-Tests were carried out on Douglas fir according to ASTM D 143. The specimens included the 25×25×100 mm3 cuboid bars for longitudinal (L), radial (R) and tangential (T) directions and the conventional 50×50×150 mm3 blocks for the perpendicular to grain (⊥) direction. Two sets of wood parameters were developed and the 3D-FEA was implemented for the two types of specimens. The 3D-FEA worked successfully provided that the stress state coming from the total wood C was uniform. However, in case of the dominance of local compressive behaviour such as bearing, crushing and fibre shear, a microscopic-level modelling technique is needed for correction of the material parameters. More details on the limitations and difficulties of 3D-FE implementation for wood were discussed.

A Simplified Thermal Load Evaluation Method for Localized Lug Stresses Beyond Sec. III Appendix-Y

2019 ◽  
Author(s):  
Tsubasa Matsumiya ◽  
Daniel Garcia-Rodriguez ◽  
Akira Nebu ◽  
Noriyuki Takamura
Keyword(s):  
Thermal Stresses ◽  
Evaluation Method ◽  
Three Dimensional ◽  
Parameter Study ◽  
Element Analysis ◽  
Class 1 ◽  
Dimensional Finite Element ◽  
3D Fea ◽  
Three Dimensional Finite Element ◽  
Load Evaluation

Abstract In this work an evaluation method for local thermal stresses on class 1 piping due to U-shaped lugs is presented. First, a three-dimensional finite element analysis (3D-FEA) is used to perform a thermal transient evaluation, obtaining the time-dependent temperature distribution of a realistic range of pipe-lug systems. These results are then used as an input for both a structural 3D-FEA and the corresponding thermal stress term in Non-Mandatory Appendix Y [1]. It was seen that the formula in Appendix-Y cannot account for the thermal stresses obtained through the detailed FEA evaluation. A parameter study using a simplified two-dimensional (2D) FEA approach, shows that the localized thermal stresses due to lugs are significantly affected by: (1) pipe-to-lug thickness ratio, (2) distance between adjacent lugs, and (3) lug height. A set of correction coefficients depending on these parameters is therefore proposed. When applying the proposed correction coefficients to the Appendix Y method, adequately conservative (when compared with 3D FEA results) stresses can be obtained. Since these correction coefficients can be obtained from simple geometric considerations, the proposed method successfully accounts for the complex lug-to-lug interaction while retaining the simplicity of the original Appendix Y approach.

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.

Sign in / Sign up

Export Citation Format

Share Document