scholarly journals A three-dimensional finite element analysis of mechanical function for 4 removable partial denture designs with 3 framework materials: CoCr, Ti-6Al-4V alloy and PEEK

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Xin Chen ◽  
Bochun Mao ◽  
Zhuoli Zhu ◽  
Jiayi Yu ◽  
Yuqing Lu ◽  
...  

Abstract Polyetheretherketone (PEEK) is a new material used for the frameworks of removable partial dentures (RPD). The questions whether the PEEK framework has similar stress distribution on oral tissue and displacement under masticatory forces as titanium alloy (Ti-6Al-4V) or cobalt-chromium alloy (CoCr) remain unclear and worth exploring. A patient’s intraoral data were obtained via CBCT and master model scan. Four RPDs were designed by 3Shape dental system, and the models were processed by three-dimensional finite element analysis. Among three materials tested, PEEK has the lowest maximum von Mises stress (VMS) on periodontal ligament (PDL), the greatest maximum VMS on mucosa, the maximum displacement on free-end of framework, and the lowest maximum VMS on framework. Results suggested that PEEK framework has a good protective effect on PDL, suggesting applications for patients with poor periodontal conditions. However, the maximum displacement of the free-end under masticatory force is not conducive for denture stability, along with large stress on the mucosa indicate that PEEK is unsuitable for patients with more loss of posterior teeth with free-end edentulism.

2020 ◽  
Vol 28 (6) ◽  
pp. 603-613 ◽  
Author(s):  
Efe Can Sivrikaya ◽  
Mehmet Sami Guler ◽  
Muhammed Latif Bekci

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.


2013 ◽  
Vol 690-693 ◽  
pp. 2831-2839 ◽  
Author(s):  
Feng Chen ◽  
Qin Feng Di ◽  
Wen Chang Wang ◽  
Wei Ping Zhu ◽  
Ming Jie Wang ◽  
...  

The development of ultra-deep drilling and extended reach drilling present many critical challenges for the threaded connections. The reliability of threaded connections must be evaluated to ensure the structural and sealing integrity of drillstring in critical applications. Three-dimensional finite element analysis of threaded connections has been performed in this paper. Different types of loading composed of make-up torque, working torque, tension and bending loading are applied to the model. The makeup characteristics of threaded connections have been analyzed, and the reliability of threaded connections under severe conditions has been evaluated. The results show that von Mises stress distribution over threaded connections is highly uneven, tooth nearby two ends was bearing the most of load. It shows that ultra-deep drilling case is even more challenge than extend reach drilling case in the threaded connections, the reliability evaluation of threaded connections is important in those challenging drilling.


2020 ◽  
Vol 46 (1) ◽  
pp. 3-12
Author(s):  
Ji-Hyeon Oh ◽  
Young-Seong Kim ◽  
Joong Yeon Lim ◽  
Byung-Ho Choi

The all-on-4 concept, which is used to rehabilitate edentulous patients, can present with mechanical complications such as screw loosening and fracture. The purpose of this study was to evaluate the stress patterns induced in the prosthetic screws by the different prosthetic screw and abutment designs in the all-on-4 concept using finite element analysis. Von Mises stress values on 6 groups of each screw type, including short and narrow screw, short abutment; short and wide screw, short abutment; long and wide screw, short abutment; short and narrow screw, long abutment; short and wide screw, long abutment; and long and wide screw, long abutment, were compared under a cantilever loading of 200 N that was applied on the farther posterior to the position of the connection between the distal implant and the metal framework. Posterior prosthetic screws showed higher stress values than anterior prosthetic screws. The stress values in posterior prosthetic screws decreased as the length and diameter increased. In conclusion, the long and wide screw design offers advantages in stress distribution when compared with the short and narrow design.


2015 ◽  
Vol 41 (2) ◽  
pp. 163-171 ◽  
Author(s):  
Gianpaolo Sannino

The aim of this work was to study the biomechanical behavior of an All-on-4 implant-supported prosthesis through a finite element analysis comparing 3 different tilt degrees of the distal implants. Three-dimensional finite element models of an edentulous maxilla restored with a prosthesis supported by 4 implants were reconstructed to carry out the analysis. Three distinct configurations, corresponding to 3 tilt degrees of the distal implants (15°, 30°, and 45°) were subjected to 4 loading simulations. The von Mises stresses generated around the implants were localized and quantified for comparison. Negligible differences in von Mises stress values were found in the comparison of the 15° and 30° models. From a stress-level viewpoint, the 45° model was revealed to be the most critical for peri-implant bone. In all the loading simulations, the maximum stress values were always found at the neck of the distal implants. The stress in the distal implants increased in the apical direction as the tilt degree increased. The stress location and distribution patterns were very similar among the evaluated models. The increase in the tilt degree of the distal implants was proportional to the increase in stress concentration. The 45° model induced higher stress values at the bone-implant interface, especially in the distal aspect, than the other 2 models analyzed.


2019 ◽  
Vol 10 (1) ◽  
pp. 68 ◽  
Author(s):  
Jung-Youl Choi ◽  
Sun-Hee Kim

The line track bearings used in the Yeoungjong Grand Bridge experienced cracks and deformations, which result in significant accelerations and displacements of the track. This study measured an acceleration and a displacement of 0.5 g and 0.5 mm, respectively. Three-dimensional finite element analysis was performed to predict the behavior of railway tracks. However, when low-maintenance cylindrical bearings were used instead of line bearings, the displacement was decreased by 93%, and the acceleration was decreased by 82%. Furthermore, it turned out that the maximum displacement of the track girder was decreased by 45% when cylindrical bearings were used.


2011 ◽  
Vol 1 (2) ◽  
pp. 55
Author(s):  
Özkan ADIGÜZEL ◽  
Sadullah KAYA ◽  
Senem YİĞİT ÖZER ◽  
Yalçın DEĞER ◽  
Emine GÖNCÜ BAŞARAN ◽  
...  

Aim: This study compared the stress distributions of endodontically treated tooth restored with carbon and titanium post during different loading conditions. Methodology: A 3-dimensional finite element model was created to represent an endodontically treated maxillary central incisor tooth with its supporting structures. Stress distribution and stress values were then calculated by considering the three dimensional von Mises stress criteria. Results: A 100-N static vertical occlusal load was applied on the node at the center of occlusal surface of the tooth. The von Mises stress values for carbon post model was on the coronal third and the cervical area of the root in the range of 353.149 and 13.878 MPa,  for titanium post model was 540.736 and 22.777 MPa. Conclusion: This study shows that the titanium post yields larger stresses than the carbon post.  How to cite this article: Adıgüzel Ö, Kaya S, Yiğit Özer S, Değer Y, Göncü Başaran E, Yavuz İ. Three-dimensional Finite Element Analysis of Endodontically Treated Tooth Restored with Carbon and Titanium Posts. Int Dent Res 2011;2:55-59. Linguistic Revision: The English in this manuscript has been checked by at least two professional editors, both native speakers of English.


2007 ◽  
Vol 35 (3) ◽  
pp. 226-238 ◽  
Author(s):  
K. M. Jeong ◽  
K. W. Kim ◽  
H. G. Beom ◽  
J. U. Park

Abstract The effects of variations in stiffness and geometry on the nonuniformity of tires are investigated by using the finite element analysis. In order to evaluate tire uniformity, a three-dimensional finite element model of the tire with imperfections is developed. This paper considers how imperfections, such as variations in stiffness or geometry and run-out, contribute to detrimental effects on tire nonuniformity. It is found that the radial force variation of a tire with imperfections depends strongly on the geometrical variations of the tire.


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