Determining the Fatigue Life of Dental Implants

2008 ◽  
Vol 2 (1) ◽  
Author(s):  
Horea T. Ilieş ◽  
Dennis Flanagan ◽  
Paul T. McCullough ◽  
Scott McQuoid
Keyword(s):  
Finite Element ◽  
Fatigue Life ◽  
Dental Implants ◽  
Morphological Characteristics ◽  
Design Tool ◽  
Implant Design ◽  
Physical Measurements ◽  
Local Bone ◽  
Removable Dental Prostheses

Dental implants are used to retain and support fixed and removable dental prostheses. In many clinical situations, local bone morphology requires dental implants that have a diameter that is significantly smaller than the typical implant diameters. In these cases, the fatigue life of the smaller diameter implants becomes a critical therapeutic parameter. However, this fatigue life depends on the implant itself, on the physical properties of the bone, as well as on other morphological characteristics that are patient dependent. In other words, this fatigue life varies greatly with each newly placed implant, but the capability to predict the fatigue life of dental implants does not exist today. In this paper, we present the first steps towards establishing such a methodology. We develop a finite element based fatigue model for rigidly mounted dental implants, and correlate its results with both analytical predictions as well as physical measurements. This implies that such a model can be used as a valid predictor of fatigue life of dental implants themselves, and can be used as a valuable implant design tool. Furthermore, we present the design of a cost effective device to measure the fatigue life of dental implants that can be either rigidly or bone mounted (in vitro). This device was used to measure the fatigue life of an initial sample of nine dental implants, and we show that the results predicted by the finite element model correlated well with our initial experimental results.

Ligament Property Optimization Within a Virtual Biomechanical Knee

2008 ◽  
Author(s):  
Jeffrey E. Bischoff ◽  
Eik Siggelkow ◽  
Daniel Sieber ◽  
Mariana Kersh ◽  
Heidi Ploeg ◽  
...  
Keyword(s):  
Material Model ◽  
Specific Model ◽  
Design Tool ◽  
Implant Design ◽  
Orthopaedic Implant ◽  
Knee Mechanics ◽  
Joint Forces ◽  
Specific Material

Specimen-specific modeling of the knee can be an effective tool for understanding knee mechanics [1–2]. It can also serve as a design tool for orthopaedic implant design through enhancing understanding of mechanics in the reconstructed knee [3], particularly when used in conjunction with instrumented components that record in vivo joint forces [4]. Techniques for developing specimen-specific computational geometric models of hard tissue and soft tissue are fairly commonplace, using imaging tools such as computed tomography (CT) and magnetic resonance (MR) in conjunction with software tools for image processing. Determination of specimen-specific material properties relies on measuring kinematics of the tissue associated with a defined load, either in vivo or in vitro, selecting an appropriate material model, and estimating values of the parameters of the model that closely match the experimental data. The goal of this work was to utilize inverse finite element (FE) analysis to determine material parameters of ligaments in a specimen-specific model of the knee, using both local and global optimization algorithms.

Effect of Polylactic Acid/Hydroxyapatite Coating on Dental Implant Using Finite Element Method

2020 ◽  
Vol 995 ◽  
pp. 103-108
Author(s):  
Hassan Mas Ayu ◽  
M.M. Mustaqieem ◽  
Rosdi Daud ◽  
A. Shah ◽  
Andril Arafat ◽  
...  
Keyword(s):  
Finite Element ◽  
Stress Distribution ◽  
Dental Implant ◽  
Bonding Strength ◽  
Load Condition ◽  
Implant Design ◽  
Element Analysis ◽  
Improve Design

Finite element analysis (FEA) has been proven to be a precise and applicable method for evaluating dental implant systems. This is because FEA allows for measurement of the stress distribution inside of the bone and various dental implant designs via simulation analysis during mastication where such measurements are impossible to perform in-vitro or in-vivo experiment. That is why the relationship between implant design and load distribution at the implant bone interface is a crucial issue to understand. This research study focuses on a static simulation and bonding strength for PLA/HA coating on V thread design of dental implant using three-dimensional finite element. The average masticatory muscle that involves in human biting such as X, Y and Z direction will be used to simulate force with load condition of 17.1N, 114.6N and 23.4N respectively. Based on result obtained, the coated dental implant model is more compatible than uncoated model due to lower maximum stress which is reduce about 16%. The coated model also shows lower deformation and higher bonding strength. Outcomes from this research provide a better understanding of stress distribution characteristics that would be useful in order to improve design of dental implant thread and evaluation of the PLA/HA bonding strength applied.

Study on statics and fatigue analysis of dental implants in the descending process of alveolar bone level

2020 ◽  
Vol 234 (8) ◽  
pp. 843-853
Author(s):  
Xuetao Zhang ◽  
Jian Mao ◽  
Yufeng Zhou ◽  
Fangqiu Ji ◽  
Xianshuai Chen
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Dental Implants ◽  
Alveolar Bone ◽  
Failure Process ◽  
Element Analysis ◽  
The Finite Element Analysis ◽  
Bone Level ◽  
Implant System

Alveolar bone atrophy can directly cause a decrease in bone level. The effect of this process on the service life of dental implants is unknown. The aim of this study was to determine the failure forms of the two-piece dental implants in the descending process of alveolar bone level, and the specific states of the components during the failure process. The CAD software SolidWorks was used to establish the model of alveolar bone and dental implants in this article. The finite element analysis was used to analyze the statics of the dental implants in the host oral model. The finite element analysis results showed that the stress concentration point of the implant and abutment in the implant system has changed greatly during the descending process of alveolar bone level, and indirectly increased the fatigue life of the same fatigue risk point. At the same time, the dental implants were tested in vitro in the descending process of alveolar bone level. Then, the fracture of the implant system was scanned by scanning electron microscope. The fatigue test results proved the finite element analysis hypothesis the central screw first fractured under fatigue and then caused an overload break of the implant and abutment.

The Effect of Varying the Density-Modulus Relationship Used to Apply Material Properties in a Finite Element Model of the Distal Ulna

2008 ◽  
Author(s):  
Rebecca L. Austman ◽  
Jaques S. Milner ◽  
David W. Holdsworth ◽  
Cynthia A. Dunning
Keyword(s):  
Computed Tomography ◽  
Finite Element ◽  
Material Properties ◽  
Cost Effective ◽  
Element Model ◽  
Implant Design ◽  
Timely Manner ◽  
Distal Ulna ◽  
Subject Specific

In many areas of orthopaedic biomechanics, such as implant design, properly developed Finite Element (FE) models can be a great companion to in-vitro studies, as they may allow a wider range of experimental variables to be explored in a cost-effective and timely manner. One challenge in developing these models is the assignment of accurate material properties to bone. Through the use of computed tomography (CT), many recent studies have developed subject-specific FE models, where material properties of bone are assigned based on density information derived from the scans. This involves the use of an equation to relate density and elastic modulus. There are several such relationships from which to choose in the literature. Most FE studies tend to use one of these multiple equations without justification or investigation into its appropriateness for the model.

Design of a Free-Floating Polycarbonate-Urethane Meniscal Implant Using Finite Element Modeling and Experimental Validation

2010 ◽  
Vol 132 (9) ◽  
Author(s):  
Jonathan J. Elsner ◽  
Sigal Portnoy ◽  
Gal Zur ◽  
Farshid Guilak ◽  
Avi Shterling ◽  
...  
Keyword(s):  
Finite Element ◽  
Pressure Distribution ◽  
Implant Design ◽  
Polycarbonate Urethane ◽  
Joint Loads ◽  
Contact Pressures ◽  
Circumferential Reinforcement ◽  
Cadaveric Knee

The development of a synthetic meniscal implant that does not require surgical attachment but still provides the biomechanical function necessary for joint preservation would have important advantages. We present a computational-experimental approach for the design optimization of a free-floating polycarbonate-urethane (PCU) meniscal implant. Validated 3D finite element (FE) models of the knee and PCU-based implant were analyzed under physiological loads. The model was validated by comparing calculated pressures, determined from FE analysis to tibial plateau contact pressures measured in a cadaveric knee in vitro. Several models of the implant, some including embedded reinforcement fibers, were tested. An optimal implant configuration was then selected based on the ability to restore pressure distribution in the knee, manufacturability, and long-term safety. The optimal implant design entailed a PCU meniscus embedded with circumferential reinforcement made of polyethylene fibers. This selected design can be manufactured in various sizes, without risking its integrity under joint loads. Importantly, it produces an optimal pressure distribution, similar in shape and values to that of natural meniscus. We have shown that a fiber-reinforced, free-floating PCU meniscal implant can redistribute joint loads in a similar pattern to natural meniscus, without risking the integrity of the implant materials.

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