Mechanical Response of PEKK and PEEK As Frameworks for Implant-Supported Full-Arch Fixed Dental Prosthesis: 3D Finite Element Analysis

Abstract Objective Polymeric framework represent an innovative approach for implant-supported dental prostheses. However, the mechanical response of ultra-high performance polymers as frameworks for full-arch prostheses under the “all-on-four concept” remains unclear. The present study applied finite element analysis to examine the behavior of polyetherketoneketone (PEKK) and polyetheretherketone (PEEK) prosthetic frameworks. Materials and Methods A three-dimensional maxillary model received four axially positioned morse-taper implants, over which a polymeric bar was simulated. The full-arch prosthesis was created from a previously reported database model, and the imported geometries were divided into a mesh composed of nodes and tetrahedral elements in the analysis software. The materials were assumed as isotropic, elastic, and homogeneous, and all contacts were considered bonded. A normal load (500 N magnitude) was applied at the occlusal surface of the first left molar after the model was fixed at the base of the cortical bone. The microstrain and von-Mises stress were selected as criteria for analysis. Results Similarities in the mechanical response were observed in both framework for the peri-implant tissue, as well as for stress generated in the implants (263–264 MPa) and abutments (274–273 MPa). The prosthetic screw and prosthetic base concentrated more stress with PEEK (211 and 58 MPa, respectively) than with PEKK (192 and 49 MPa), while the prosthetic framework showed the opposite behavior (59 MPa for PEEK and 67 MPa for PEKK). Conclusion The main differences related to the mechanical behavior of PEKK and PEEK frameworks for full-arch prostheses under the “all-on-four concept” were reflected in the prosthetic screw and the acrylic base. The superior shock absorbance of PEKK resulted in a lower stress concentration on the prosthetic screw and prosthetic base. This would clinically represent a lower fracture risk on the acrylic base and screw loosening. Conversely, lower stress concentration was observed on PEEK frameworks.

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Mechanical and Optimization Analyses for Novel Wound Composite Axial Impeller

Volume 11: Mechanics of Solids, Structures and Fluids ◽

10.1115/imece2009-12938 ◽

2009 ◽

Cited By ~ 2

Author(s):

Jifeng Wang ◽

Qubo Li ◽

Norbert Mu¨ller

Keyword(s):

Finite Element Analysis ◽

Finite Element ◽

High Speed ◽

High Performance ◽

Low Cost ◽

Three Dimensional ◽

Von Mises Stress ◽

Loading Conditions ◽

Element Analysis ◽

Wound Composite

A mechanical and optimal analyses procedure is developed to assess the stresses and deformations of Novel Wound Composite Axial-Impeller under loading conditions particular to centrifuge. This procedure is based on an analytical method and Finite Element Analysis (FEA, commercial software ANSYS) results. A low-cost, light-weight, high-performance, composite turbomachinery impeller from differently designed patterns will be evaluated. Such impellers can economically enable refrigeration plants using water as a refrigerant (R718). To create different complex patterns of impellers, MATLAB is used for creating the geometry of impellers, and CAD software UG is used to build three-dimensional impeller models. Available loading conditions are: radial body force due to high speed rotation about the cylindrical axis and fluid forces on each blade. Two-dimensional plane stress and three-dimensional stress finite element analysis are carried out using ANSYS to validate these analytical mechanical equations. The von Mises stress is investigated, and maximum stress and Tsai-Wu failure criteria are applied for composite material failure, and they generally show good agreement.

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Evaluation of Zirconia and Cobalt-Chrome for Custom-Milled Framework Design for an Implant-Supported Full-Arch Fixed Dental Prosthesis: A Finite Element Analysis

Dental Oral Biology and Craniofacial Research ◽

10.31487/j.dobcr.2020.04.02 ◽

2020 ◽

pp. 1-5

Author(s):

João Paulo Mendes Tribst ◽

Datte CE ◽

Silveira MPM ◽

de Andrade GS ◽

Bottino MA ◽

...

Keyword(s):

Finite Element ◽

Mechanical Response ◽

Dental Prosthesis ◽

Von Mises Stress ◽

Application Site ◽

Homogeneous Material ◽

High Survival ◽

Element Analysis ◽

Framework Design ◽

Fixed Dental Prosthesis

The demands for aesthetics in implant-supported full-arch prosthesis increased the use of zirconia as framework material due to its aesthetics, biocompatibility and high survival rate. The aim of this study was to compare the mechanical response of Zirconia and CoCr custom-milled framework indicated for maxillary prosthetic rehabilitations using the Finite Element Method. To perform this simulation, a custom-milled framework design for an implant-supported full-arch fixed dental prosthesis was used. The geometries of bone, prosthesis, implants, abutments and prosthetic screw were modelled. The mechanical properties for each isotropic and homogeneous material were simulated. Two frameworks were simulated (YZTP and CoCr Alloy). A load of 500 N load was applied on the occlusal surface of the right upper first molar. The results were analysed in terms of displacement, von Mises stress and microstrain. After the simulation processing, it was not possible to observe difference for prosthesis displacement or stress concentration regarding the framework material. The use of YTZP exhibited the lowest stress magnitude for implant (60 MPa) near the load application site, in comparison with the metallic framework (76 MPa in the same region). The same behaviour was calculated for the microstrain results in peri-implant region. The use of YZTP to perform a custom-milled framework design for an implant-supported full-arch fixed dental prosthesis may have acceptable mechanical response for the analysed structures.

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

BMC Oral Health ◽

10.1186/s12903-021-01809-4 ◽

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.

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Cross-Weld Tensile Properties of Girth Welds for Strain-Based Designed Pipelines

Volume 3: Materials and Joining; Pipeline Automation and Measurement; Risk and Reliability, Parts A and B ◽

10.1115/ipc2006-10400 ◽

2006 ◽

Cited By ~ 1

Author(s):

J. T. Bowker ◽

J. A. Gianetto ◽

G. Shen ◽

W. Tyson ◽

D. Horsley

Keyword(s):

Finite Element Analysis ◽

Finite Element ◽

Stress Concentration ◽

Weld Metal ◽

Tensile Properties ◽

True Strain ◽

Standard Test ◽

Pipe Material ◽

Lower Stress ◽

Element Analysis

For strain-based designed pipelines it is important to understand the relative tensile properties of both weld metal and pipe material in the pipe axial direction. The evaluation of weld metal tensile properties has typically involved extracting all-weld-metal tensile samples in the direction of the weld. In this study an evaluation of the application of “waisted” tensile samples to generate data has been conducted. Initial studies focused on finite element analysis to generate geometry factors for a range of specimen configurations to correct for the level of stress triaxiality. These factors were then applied to samples extracted from X70 and X100 pipe material to establish the validity of this approach. It was shown that, regardless of the radius of waisted specimens, very good agreement was obtained between the geometry-factor-corrected stress-strain curves and those generated from standard test specimens at true strains above 0.02. To achieve a better agreement between the corrected and standard tensile curves in and around yield it was necessary to use samples with a large radius (9 mm) where the stress concentration was low. Finite element analysis provided supporting evidence with respect to the effect of stress concentration associated with different specimen radii on the yielding pattern. These waisted samples were used to measure the tensile properties in all-weld-metal and cross-weld-metal directions for an X70 double joint (DJ) weld and an X100 mechanized pulsed gas metal arc (P-GMA) weld. Waisted samples taken from the double joint weld on X70 with radii of 3 mm and 9 mm showed no difference with respect to their orientation. Once stress-strain behaviour was corrected for geometry, the curves were in excellent agreement with the standard test specimens above 0.01 true strain in the case of the sample of radius 3 mm and for the whole curve for the sample with radius 9 mm. An assessment of the X100 weld identified a small difference between all-weld-metal and cross-weld-metal directions, with the latter displaying a lower stress between yielding and 0.03 true strain. The use of waisted samples of larger radius generated much better agreement with the standard specimens associated with their lower stress concentration. Because of the finite weld width, consideration needs to be given to the extent to which the reduced section may extend beyond the weld and the potential effect of mismatch in strength.

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Kyphoplasty of Osteoporotic Fractured Vertebrae: A Finite Element Analysis about Two Types of Cement

BioMed Research International ◽

10.1155/2019/9232813 ◽

2019 ◽

Vol 2019 ◽

pp. 1-7

Author(s):

Carolin Meyer ◽

Kerstin van Gaalen ◽

Tim Leschinger ◽

Max J. Scheyerer ◽

Wolfram F. Neiss ◽

...

Keyword(s):

Finite Element Analysis ◽

Finite Element ◽

Vertebral Body ◽

Lumbar Vertebrae ◽

Von Mises Stress ◽

Vertebral Compression Fractures ◽

Stress Concentrations ◽

Lower Stress ◽

Element Analysis ◽

Von Mises

If conservative treatment of osteoporotic vertebral compression fractures fails, vertebro- or kyphoplasty is indicated. Usually, polymethylmethacrylate cement (PMMA) is applied coming along with many disadvantageous features. Aluminum-free glass-polyalkenoate cement (GPC) appears to be a benefit alternative material. This study aimed at comparing the mean stress values in human vertebrae after kyphoplasty with PMMA and GPC (IlluminOss™) at hand of a finite element analysis. Three models were created performing kyphoplasty using PMMA or IlluminOss™, respectively, at two native, human lumbar vertebrae (L4) while one remains intact. Finite element analysis was performed using CT-scans of every vertebra. Moreover the PMMA-treated vertebra was used as a model as analyses were executed using material data of PMMA and of GPC. The unimpaired, spongious bone showed potentials of 0.25 MPa maximally. After augmentation stress levels showed fivefold increase, rising from externally to internally, revealing stress peaks at the ventral border of the spinal canal. At central areas of cement 1 MPa is measured in both types of cement. Around these central areas the von Mises stress decreased about 25-50% (0.5-0.75 MPa). If workload of 500 N was applied, the stress appeared to be more centralized at the IlluminOss™-model, similar to the unimpaired. Considering the endplates the GPC model also closely resembles the unimpaired. Comparing the PMMA-treated vertebral body and the GPC-simulation, there is an obvious difference. While the PMMA-treated model showed a central stress peak of 5 MPa, the GPC-simulation of the same vertebral body presents lower stress of 1.2-2.5 MPa. Finite element analysis showed that IlluminOss™ (GPC), used in kyphoplasty of vertebral bodies, creates lower level stress and strain compared to standardly used PMMA, leading to lower stress concentrations on the cranial and caudal vertebral surface especially. GPC appears to own advantageous biological and clinical relevant features.

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Self-drilling versus Self-tapping Screws: A 3D Finite Element Analysis

Craniomaxillofacial Trauma & Reconstruction ◽

10.1177/1943387520904212 ◽

2020 ◽

pp. 194338752090421

Author(s):

Kumar K Vineeth ◽

Kavitha Prasad ◽

Tanvy Sansgiri ◽

K. Ranganath ◽

V Shwetha ◽

...

Keyword(s):

Finite Element Analysis ◽

Finite Element ◽

Stress Concentration ◽

Computer Aided Design ◽

Von Mises Stress ◽

Mandibular Fractures ◽

Element Analysis ◽

3D Finite Element ◽

3D Finite Element Analysis ◽

Bone Interface

Self-tapping and self-drilling screws are two modalities available for plate fixation. When compared to self-drilling, self-tapping screws have a few drawbacks like screw loosening, thermal osteolysis, equipment dependent, and time-consuming. Aim: The aim of this study was to compare the efficacy of self-tapping and self-drilling screws with relation to plate retention and stability in internal fixation of mandibular fractures using 3D finite element analysis (FEA). Objectives: The objective of this study was to determine the influence of screw placement technique on stress concentration and deformation occurring at the screw–bone interface in self-drilling and self-tapping screws. Materials and Methods: A 3D computer-aided design modeling system was used to build a trilaminate mandibular bone, self-tapping screw and self-drilling screw, and a 2-holed miniplate with gap that were converted into finite element models using Hypermesh 13.0 software. Material properties and boundary conditions were assigned to these models. Pullout, torque, and torsional forces were applied to evaluate the stress concentration and deformation at the screw–bone interface. Results: The comparison of stress concentration and deformation values between the two types of screws was interpreted using ANSYS software version 14.5. Results of torque test, pullout test, and torsional test showed maximum Von Mises stress, and deformation around the screw–bone interface was higher in self-tapping screw than in self-drilling screw. Conclusion: Within the limitations of the 3D FEA, the findings provided significant evidence to suggest that self-tapping screws have a greater incidence of fatigue when compared to self-drilling screws as there was more stress distribution and deformation at their screw–bone interface.

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Finite Element Analysis of Stress in Bone and Abutment-Implant Interface under Static and Cyclic Loadings

Frontiers in Dentistry ◽

10.18502/fid.v17i21.4315 ◽

2020 ◽

Author(s):

Saeed Nokar ◽

Hamid Jalali ◽

Farideh Nozari ◽

Mahnaz Arshad

Keyword(s):

Finite Element Analysis ◽

Finite Element ◽

Stress Concentration ◽

Stress Distribution ◽

Maximum Stress ◽

Von Mises Stress ◽

Element Analysis ◽

Bone Implant ◽

Factors Affecting ◽

Von Mises

Objectives: The success of implant treatment depends on many factors affecting the bone-implant, implant-abutment, and abutment-prosthesis interfaces. Stress distribution in bone plays a major role in success/failure of dental implants. This study aimed to assess the pattern of stress distribution in bone and abutment-implant interface under static and cyclic loadings using finite element analysis (FEA). Materials and Methods: In this study, ITI implants (4.1×12 mm) placed at the second premolar site with Synocta abutments and metal-ceramic crowns were simulated using SolidWorks 2007 and ABAQUS software. The bone-implant contact was assumed to be 100%. The abutments were tightened with 35 Ncm preload torque according to the manufacturer’s instructions. Static and cyclic loads were applied in axial (116 Ncm), lingual (18 Ncm), and mesiodistal (24 Ncm) directions. The maximum von Mises stress and strain values were recorded. Results: The maximum stress concentration was at the abutment neck during both static and cyclic loadings. Also, maximum stress concentration was observed in the cortical bone. The loading stress was higher in cyclic than static loading. Conclusion: Within the limitations of this study, it can be concluded that the level of stress in single-unit implant restorations is within the tolerable range by bone.

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3D Finite Element Analysis of Rotary Instruments in Root Canal Dentine with Different Elastic Moduli

Applied Sciences ◽

10.3390/app11062547 ◽

2021 ◽

Vol 11 (6) ◽

pp. 2547 ◽

Cited By ~ 1

Author(s):

Carlo Prati ◽

João Paulo Mendes Tribst ◽

Amanda Maria de Oliveira Dal Piva ◽

Alexandre Luiz Souto Borges ◽

Maurizio Ventre ◽

...

Keyword(s):

Finite Element Analysis ◽

Finite Element ◽

Root Canal ◽

Elastic Moduli ◽

Reaction Force ◽

Von Mises Stress ◽

Elastic Behavior ◽

Element Analysis ◽

Heat Treated ◽

Von Mises

The aim of the present investigation was to calculate the stress distribution generated in the root dentine canal during mechanical rotation of five different NiTi endodontic instruments by means of a finite element analysis (FEA). Two conventional alloy NiTi instruments F360 25/04 and F6 Skytaper 25/06, in comparison to three heat treated alloys NiTI Hyflex CM 25/04, Protaper Next 25/06 and One Curve 25/06 were considered and analyzed. The instruments’ flexibility (reaction force) and geometrical features (cross section, conicity) were previously investigated. For each instrument, dentine root canals with two different elastic moduli(18 and 42 GPa) were simulated with defined apical ratios. Ten different CAD instrument models were created and their mechanical behaviors were analyzed by a 3D-FEA. Static structural analyses were performed with a non-failure condition, since a linear elastic behavior was assumed for all components. All the instruments generated a stress area concentration in correspondence to the root canal curvature at approx. 7 mm from the apex. The maximum values were found when instruments were analyzed in the highest elastic modulus dentine canal. Strain and von Mises stress patterns showed a higher concentration in the first part of curved radius of all the instruments. Conventional Ni-Ti endodontic instruments demonstrated higher stress magnitudes, regardless of the conicity of 4% and 6%, and they showed the highest von Mises stress values in sound, as well as in mineralized dentine canals. Heat-treated endodontic instruments with higher flexibility values showed a reduced stress concentration map. Hyflex CM 25/04 displayed the lowest von Mises stress values of, respectively, 35.73 and 44.30 GPa for sound and mineralized dentine. The mechanical behavior of all rotary endodontic instruments was influenced by the different elastic moduli and by the dentine canal rigidity.

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