scholarly journals Evaluation of Fatigue Life for Dental Implants Using FEM Analysis

Prosthesis ◽  
2021 ◽  
Vol 3 (4) ◽  
pp. 300-313
Author(s):  
Babak Ziaie ◽  
S. Mohammad Reza Khalili
Keyword(s):  
Fatigue Life ◽  
Life Prediction ◽  
3D Model ◽  
Vertical Direction ◽  
Fem Analysis ◽  
Mechanical Analysis ◽  
Implant Abutment ◽  
The Stability ◽  
Implant System ◽  
Abutment Screw

The purpose of this study is to numerically analyze a 3D model of an implant under fatigue loads. A bone and a V shape implant were modeled using SolidWorks2008 software. In order to obtain an exact model, the bone was assumed as a linear orthotropic material. Mechanical loads were applied in terms of fastening torque to the abutment and mastication force applied at the top of the crown. The abutment was tightened into the implant by applying a 35 N.cm torque causing tensile stress within the abutment screw as a preload that is harmful not only for the fatigue life of the abutment, but also for the stability of the implant-abutment interface. A 700 N force at an angle of 30 degrees to the vertical direction was applied to the crown. The mechanical analysis results showed that the abutment is the critical component of the implant system in terms of fatigue failure. This is due to the fact that the tensile preloads originated from the fastening torque. The results were presented in terms of fatigue life in the abutment. Fatigue life of the abutment and implant were calculated based on the Goodman, Soderberg, Smith–Watson–Topper (SWT), and Marrow theories. According to the results of the fatigue life prediction, abutment screws may fail after about 3 × 105 cycles. The predicted results by the Goodman theory are at a very good accordance with the clinical data.

scholarly journals Biomechanical Evaluation of the Effects of Implant Neck Wall Thickness and Abutment Screw Size: A 3D Nonlinear Finite Element Analysis

2020 ◽  
Vol 10 (10) ◽  
pp. 3471 ◽  
Author(s):  
Ming-Dih Jeng ◽  
Yang-Sung Lin ◽  
Chun-Li Lin
Keyword(s):  
Finite Element ◽  
Wall Thickness ◽  
Alveolar Bone ◽  
Nonlinear Finite Element ◽  
Bone Strain ◽  
Concentrated Force ◽  
Element Analysis ◽  
Implant Abutment ◽  
Implant System ◽  
Abutment Screw

In this study, we evaluate the influence of implant neck wall thickness and abutment screw size on alveolar bone and implant component biomechanical responses using nonlinear finite element (FE) analysis. Twelve internal hexagon Morse taper implant–abutment connection FE models with three different implant sizes (diameters 4, 5, and 6 mm), secured with 1.4, 1.6, and 1.8 mm abutment screws to fit with three unilateral implant neck wall thicknesses of 0.45, 0.50, and 1.00 mm, were constructed to perform simulations. Nonlinear contact elements were used to simulate realistic interface fixation within the implant system. A 200 N concentrated force was applied toward the center of a hemispherical load cap and inclined 30° relative to the implant axis as the loading condition. The simulation results indicated that increasing the unilateral implant neck wall thickness from 0.45 to 1.00 mm can significantly decrease implant, abutment, and abutment screw stresses and bone strain, decreased to 58%, 48%, 54%, and 70%, respectively. Variations in abutment screw size only significantly influenced abutment screw stress, and the maximum stress dissipation rates were 10% and 29% when the diameter was increased from 1.4 to 1.6 and 1.8 mm, respectively. We conclude that the unilateral implant neck wall thickness is the major design factor for the implant system and implant neck wall thickness in effectively decreasing implant, abutment, and abutment screw stresses and bone strain.

Influence of implant/abutment joint designs on abutment screw loosening in a dental implant system

2005 ◽  
Vol 75B (2) ◽  
pp. 457-463 ◽  
Author(s):  
Tsuyoshi Kitagawa ◽  
Yasuhiro Tanimoto ◽  
Misako Odaki ◽  
Kimiya Nemoto ◽  
Masahiro Aida
Keyword(s):  
Dental Implant ◽  
Screw Loosening ◽  
Implant Abutment ◽  
Implant System ◽  
Abutment Screw

Prebending Coiled Tubing and Its Fatigue Life Prediction

2012 ◽  
Vol 134 (3) ◽  
Author(s):  
Li Zifeng ◽  
Li Xuejiao ◽  
Wang Peng
Keyword(s):  
Fatigue Life ◽  
Life Prediction ◽  
Interpolation Method ◽  
New Technology ◽  
High Stress ◽  
Mechanical Analysis ◽  
Fatigue Life Prediction ◽  
Oil Drilling ◽  
Coiled Tubing ◽  
Stress Cycling

Coiled tubing is widely used in oil drilling and production operations. However, extreme high stress variation of coiled tubing during the processes of pulling out, rolling in the reel, and passing through the gooseneck makes coiled tubing fatigue failure easily. Thus, it is of great importance to increase coiled tubing fatigue life. This paper introduces the new technology to improve the fatigue life of coiled tubing—the prebending coiled tubing technology; proceeds mechanical analysis and strength check of the prebending coiled tubing; analyzes stress cycling characteristics of the prebending coiled tubing in field operations; establishes the fatigue life prediction model of prebending coiled tubing under arbitrary cycle, on the basis of fatigue experimental data under the symmetric cycle and the pulsating cycle, with fitting and interpolation method; makes simple comparison of the fatigue life of the prebending coiled tubing with that of the straight coiled tubing. Preliminary calculations show that the prebending coiled tubing technology may improve the fatigue life of coiled tubing multiple times.

scholarly journals Influence of Implant-Abutment Contact Surfaces and Prosthetic Screw Tightening on the Stress Concentration, Fatigue Life and Microgap Formation: A Finite Element Analysis

Oral ◽  
2021 ◽  
Vol 1 (2) ◽  
pp. 88-101
Author(s):  
João Paulo Mendes Tribst ◽  
Amanda Maria de Oliveira Dal Piva ◽  
Laís Regiane da Silva-Concílio ◽  
Pietro Ausiello ◽  
Les Kalman
Keyword(s):  
Fatigue Life ◽  
Safety Factor ◽  
Numerical Models ◽  
Stress Generation ◽  
Von Mises Stress ◽  
Element Analysis ◽  
Applied Torque ◽  
Implant Abutment ◽  
Contact Surfaces ◽  
Abutment Screw

The purpose of this in silico study was to investigate the effect of abutment screw torque and implant-abutment contact surfaces on the stress generation, microgap formation and simulated fatigue life of an external hexagon connection under oblique loading. Three-dimensional numerical models of the external hexagon implant were modeled containing two different implant-abutment contact surfaces (with and without contacting the hexagon axial walls) as well as using screw torques of 20 Ncm or 30 Ncm. Following the ISO 14801, an oblique load of 100 N was applied to the prosthesis. The von Mises stress, microgap formation, safety factor and fatigue life were obtained. The stresses in the abutment screw and implant were minimally influenced by the screw torque. However, this minimal stress in the screw with a 30 Ncm torque reduced the calculated fatigue life in comparison with 20 Ncm when the external hexagon axial walls were not in contact at the implant-abutment interface. The safety factor for the implant was higher when using minimal surfaces at the abutment-interfaces; however, it compromised the screw safety factor increasing its failure probability. The higher the screw torque, the lower was the microgap formation at the implant-abutment interface. However, the calculated residual stress is proportional to the applied torque, reducing the fatigue life in the screw. This effect can be attenuated using an implant-abutment system with more contacting surfaces.

Thermo-mechanical Analysis and Fatigue Life Prediction for Integrated Circuits (ICs)

2021 ◽  
Author(s):  
Aziz Oukaira ◽  
Djallel Eddine Touati ◽  
Ahmad Hassan ◽  
Mohamed Ali ◽  
Yvon Savaria ◽  
...  
Keyword(s):  
Fatigue Life ◽  
Integrated Circuits ◽  
Life Prediction ◽  
Mechanical Analysis ◽  
Fatigue Life Prediction

A Study on the Fatigue Life Prediction for Bending Pipe

2011 ◽  
Vol 415-417 ◽  
pp. 2219-2225
Author(s):  
Soo Park ◽  
Hui Hwan Kwon ◽  
Jae Mean Koo ◽  
Chang Sung Seok ◽  
Du Han Jung ◽  
...  
Keyword(s):  
Residual Stress ◽  
Fatigue Life ◽  
Life Prediction ◽  
Testing Machine ◽  
Fem Analysis ◽  
Fatigue Life Prediction ◽  
Straight Pipe ◽  
Power Sources ◽  
Uniaxial Testing ◽  
New Equation

Mechanical structures with power sources experience repeated force produced by motors. As a result, the life of the pipes reduces and ultimately, the pipes collapse. In most cases, the U-shape pipe is made from a straight pipe by complicated bending work. During this work process, plastic deformation of the pipe produces residual stress in the pipe. The residual stress significantly affects the fracture behavior of the pipe. In this paper, fatigues tests of U-shape bending pipe are performed by uniaxial testing machine and residual stresses were evaluated by FEM analysis. So we established the relation between residual stress and fatigue life. And we suggested new equation for fatigue life prediction using the residual stress of U-shape bending pipe.

Dynamic and static load performance of dental biomaterial systems with conical implant-abutment connections

2020 ◽  
Vol 31 (5) ◽  
pp. 319-328
Author(s):  
Mehmet Can Basgil ◽  
Cem Kurtoglu ◽  
Koray Soygun ◽  
Yunus Uslan ◽  
Teyfik Demi̇r
Keyword(s):  
Dynamic Loading ◽  
Fracture Strength ◽  
Static Loading ◽  
Sem Analysis ◽  
Control Group ◽  
Compression Load ◽  
Implant Abutment ◽  
The Stability ◽  
Implant System

BACKGROUND: The stability of the implant-abutment interface is an important factor that influences load distribution on the marginal bone. OBJECTIVE: In this study, three dental implants with the same connection were subjected to different dynamic loading cycles. The fracture strengths and the horizontal compatibility of implants were assessed. METHODS: Eighty four implant specimens were embedded in a polyacetal cylinder as simulated bone loss of 3 mm from the implant platform. Three of the implants were used to determine the endurance limit. The other specimens were subdivided into four subgroups (n = 6): three for dynamic + static loading, and one for static loading (control group). The tests were performed by applying a compression load. The dynamic loading experiments included three different cycles with endurance upper limit loads at a frequency of 10 Hz. RESULTS: The differences between the fracture strength values of the implant brands were found to be statistically significant. However, there were no meaningful differences between the fracture strength values of implants of the same brand. The specimens of the DTI implant system had the lowest strength (647.9 ± 41.5 N) and the SEM analysis indicated that the Implantium implant system had the shortest horizontal gaps. CONCLUSIONS: There was a negative correlation between the fracture strengths and size of the microgaps. The importance of these in vitro results needs to be validated by clinical trials because the loads in the mouth can be applied from various angles.

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