A SIMPLE AND EFFICIENT METHODOLOGY TO IMPROVE DESIGN PROPOSALS OF DENTAL IMPLANTS — A DESIGN CASE STUDY

2015 ◽  
Vol 27 (04) ◽  
pp. 1550037 ◽  
Author(s):  
G. Uzcátegui ◽  
E. Dávila ◽  
M. Cerrolaza

Objective: To propose a methodology based on virtual simulation to assist in the design proposals of dental implants. Methods: The finite element method (FEM) was used to analyze the biomechanical dental implant system behavior, determining von Mises stress distribution induced by functional loads, varying parameter as load direction and geometric characteristic of the implant (taper, length, abutment angulation, thread pitch and width pitch). A final design was obtained by considering the parameters that showed improved performance. The estimated lifetime of the final design was calculated by reproducing in a virtual way the experimental fatigue test required by the ISO:14801 standards. Results: For all the studied cases, the maximum stresses were obtained in the connecting screw under oblique loads (OLs). The estimated lifetime for this critical part is at least 5 × 106 cycles, which meets the requirement of the ISO:14801. In bone tissue, the largest stresses were concentrated in cortical bone, in the zone surrounding the implant, in good agreement with previous reports. Conclusions: A dental implant design was obtained and validated through a simple and efficient methodology based on the application of numerical methods and computer simulations.

2020 ◽  
Vol 899 ◽  
pp. 81-93
Author(s):  
Nur Faiqa Ismail ◽  
M. Saiful Islam ◽  
Solehuddin Shuib ◽  
Rohana Ahmad ◽  
M. Amar Shahmin

This research was conducted to provide a feasible method for reconstructing the 3D model of mandibular bone to undergo finite element analysis to investigate von Mises stress, deformation and shear stress located at the cortical bone, cancellous one and neck implant of the proposed dental implant design. Dental implant has become a significant remedial approach but although the success rate is high, the fixture failure may happen when there are insufficient host tissues to initiate and sustain the osseointegration. Computerised Tomography scan was conducted to generate head images for bone reconstruction process. MIMICS software and 3-matic software were used to develop the 3D mandibular model. The reconstructed mandibular model was then assembled with five different 3D models of dental implants. Feasible boundary conditions and material properties were assigned to the developed muscle areas and joints. The highest performance design with the best responses was the design B with the value for the von Mises stress for the neck implant, cortical and cancellous bone were 7.53 MPa, 16.91 MPa and 1.34 MPa respectively. The values for the maximum of micromotion for the neck implant, cortical and cancellous bone of design B were 20.60 μm, 21.17 μm and 5.83 μm respectively. Shear stress for neck implant, cortical and cancellous bone for this design were 0.15 MPa, 4.74 MPa and 1.54 MPa respectively. The design with a cone shaped hole which is design B was the proper design when compared with other designs in terms of von Misses stress, deformations and shear stress.


2018 ◽  
Vol 2018 ◽  
pp. 1-10 ◽  
Author(s):  
Fatma Bayata ◽  
Cengiz Yildiz

The selection of materials has a considerable role on long-term stability of implants. The materials having high resistance to fatigue are required for dental implant applications since these implants are subjected to cyclic loads during chewing. This study evaluates the performance of different types of materials (AISI 316L stainless steel, alumina and its porous state, CoCr alloys, yttrium-stabilized zirconia (YSZ), zirconia-toughened alumina (ZTA), and cp Ti with the nanotubular TiO2 surface) by finite element analysis (FEA) under real cyclic biting loads and researches the optimum material for implant applications. For the analysis, the implant design generated by our group was utilized. The mechanical behavior and the life of the implant under biting loads were estimated based on the material and surface properties. According to the condition based on ISO 14801, the FEA results showed that the equivalent von Mises stress values were in the range of 226.95 MPa and 239.05 MPa. The penetration analysis was also performed, and the calculated penetration of the models onto the bone structure ranged between 0.0037389 mm and 0.013626 mm. L-605 CoCr alloy-assigned implant model showed the least penetration, while cp Ti with the nanotubular TiO2 surface led to the most one. However, the difference was about 0.01 mm, and it may not be evaluated as a distinct difference. As the final numerical evaluation item, the fatigue life was executed, and the results were achieved in the range of 4 × 105 and 1 × 109 cycles. These results indicated that different materials showed good performance for each evaluation component, but considering the overall mechanical performance and the treatment process (implant adsorption) by means of surface properties, cp Ti with the nanotubular TiO2 surface material was evaluated as the suitable one, and it may also be implied that it displayed enough performance in the designed dental implant model.


2017 ◽  
Vol 13 ◽  
pp. 97
Author(s):  
Luboš Řehounek ◽  
František Denk ◽  
Aleš Jíra

A newly developed reference dental implant specimen type was subjected to numerical simulations of osseointegration. The goal of these tests was to optimize the geometry of the implant so as to reduce local stress concentrations and provide a better flow of stress through the whole implant body. Conditions for osseointegration were considered when evaluating the anchoring system of the implant in regard to its placement in the human cancellous and cortical bone. Numerical simulations showed that stress concentrations occur mostly in the upper cylindrical part of the implant. By increasing the width of this cylindrical part, we were able to reduce the maximum values of von-Mises stress by 20 %.


2020 ◽  
Vol 62 (8) ◽  
pp. 775-782
Author(s):  
S. Hedia Hassan ◽  
Ismail M. R. Najjar ◽  
Noha Fouda ◽  
Fisal W. Al-Thobiani ◽  
Hattan A. Timraz

Abstract Metallic dental implants such as titanium and stainless steel have an elastic modulus 5-14 times greater than that of compact bone (15 GPa). These stiff implants do not adequately strain the bone, which can result in bone resorption through a phenomenon referred to as stress shielding. The implant length and diameter has a significant influence on the stress distribution within the surrounding jawbone. Therefore, the objective of this investigation is to optimize the material and the dimensions of a dental implant. A numerical solution of a 3D finite element analysis using ANSYS software was conducted to achieve this purpose. It was concluded that by using stainless steel, titanium or gold dental implants with a large diameter and short length the values of the maximum von Mises stress values in cortical bone were increased. The maximum increase in von Mises stress can be obtained by using a stainless steel implant. This dental implant will reduce the stress shielding effect as well as yield suitable values with respect to von Mises stress for both porcelain crowns and dental implants, thus increasing the service life of the implant.


2017 ◽  
Vol 24 (5) ◽  
pp. 747-754 ◽  
Author(s):  
Hadi Asgharzadeh Shirazi ◽  
Majidreza Ayatollahi ◽  
Alireza Karimi ◽  
Mahdi Navidbakhsh

AbstractFunctionally graded biomaterials (FGBMs) have received significant attention in the recent years as potential candidates for the next generation of dental implant improvement. This happened due to their unique advantages and their ability to satisfy the requirements of both biomechanical and biocompatibility properties simultaneously. This study was aimed to analyze the effects of two radial and axial FGBM dental implants on the stress distribution near the dental implant-bone interface under a static load using finite element method (FEM). The model was restrained on a base supporting bone and vertically loaded with a force of 100 N on the top of the abutment. In the FGBM models, the implants are made of a combination of bioceramic and biometal composition, with properties that change gradually and continuously in the radial and axial directions. The numerical results indicated that the use of both radial and axial FGBM dental implants reduced the maximum von Mises stress in the cortical and the cancellous bones in comparison with the common titanium one, which leads to faster bone regeneration and early stabilization of dental implant system. The findings of the present study may have implications not only for understanding the stresses and deformations around the implant-bone interface but also for improving the performance as well as application of FGBMs in dental implant materials.


2020 ◽  
Author(s):  
Chaushu Liat ◽  
Chaushu Gavriel

Abstract A new two-piece dental implant, having a replaceable thin titanium sleeve in its 5mm crestal part was designed. The use of a sleeve of near 0.2mm thickness reduces implant diameter by 0.4mm. Narrower diameter implants may increase the likelihood of component fracture in dental implant systems. 14 two-piece dental implants, with 25° abutment angle were subjected to a dynamic fatigue test according to DIN EN ISO 14801. The highest load at which a runout (non-failure) occurred at 5x106 cycles, amounted to 575 N. According to DIN EN ISO 14801, this load level was confirmed with n=3 samples. The Wöhler curve was determined. Accordingly, the runout at 106 cycles can be anticipated as 625N. The new two-piece Implant B™ design using a 0.2 mm sleeve is compatible with the DIN EN ISO 14801 standard for dimensions of 4.2mm diameter and 13mm length. It withstands dynamic fatigue test at least as good as any other standard endosseous implant.


2021 ◽  
Vol 30 ◽  
pp. 81-86
Author(s):  
Luboš Řehounek ◽  
Aleš Jíra ◽  
Gabriela Javorská ◽  
Daniel Bodlák

Most modern dental implants differentiate in regard to the fixation of the abutment into two main categories - the external or internal hexagon or octagon. We performed mechanical tests according to the ČSN EN ISO 14801 standard on a dental implant variant using the external hex. We found that failure of all implant specimens occured below the screw head. To improve the current geometry, we performed numerical analysis of an alternative variant (internal hex) and compared it with analysis of the current geometry (external hex). It was found that the stress distribution of the variant with internal hex is preferable to the old variant. Although extreme values of shear stress in the corresponding plane of loading are higher, they do not concentrate below the screw head, where the screw itself is thinner and more prone to breaking. Therefore, it seems that the new variant of the dental implant is stronger, which is still to be proven by mechanical tests.


Author(s):  
Mateus Favero Barra Grande ◽  
Marcelo Lucchesi Teixeira ◽  
André Antônio Pelegrine ◽  
Guilherme Da Rocha Scalzer Lopes ◽  
Julio Ferraz Campos ◽  
...  

The effect of the different dental implants positioning region on the stress performance of the implant-supported prosthesis is not yet clear. This study evaluated the dental treatment with six dental implants in three different models and three different occlusal loading conditions, in terms of the biomechanical response of implants, prosthetic screw and maxilla, using three-dimensional finite element analysis. The finite element models were modelled containing external hexagon implants, as well as a Cobalt-Chromium superstructure. Three types of loads were applied: in the area of ​​the central incisors, first premolar and in the second molars. For the finite element simulations, the von-Mises stress peaks in the implant and in the surrounding cortical bone were analyzed. All recorded results reported higher values ​​for the implant-supported prosthesis in group C compared to the groups A and B. The highest stress values, ​​regardless the evaluated model, was in the prosthesis in group C and in screws, the smallest were in group A.


Prosthesis ◽  
2019 ◽  
Vol 1 (1) ◽  
pp. 41-53 ◽  
Author(s):  
Cicciù ◽  
Cervino ◽  
Terranova ◽  
Risitano ◽  
Raffaele ◽  
...  

In recent years the science of dental materials and implantology have taken many steps forward. In particular, it has tended to optimize the implant design, the implant surface, or the connection between implant and abutment. All these features have been improved or modified to obtain a better response from the body, better biomechanics, increased bone implant contact surface, and better immunological response. The purpose of this article, carried out by a multidisciplinary team, is to evaluate and understand, through the use also of bioengineering tests, the biomechanical aspects, and those induced on the patient's tissues, by dental implants. A comparative analysis on different dental implants of the same manufacturer was carried out to evaluate biomechanical and molecular features. Von Mises analysis has given results regarding the biomechanical behavior of these implants and above all the repercussions on the patient's tissues. Knowing and understanding the biomechanical characteristics with studies of this type could help improve their characteristics in order to have more predictable oral rehabilitations.


2021 ◽  
Vol 4 (1) ◽  
pp. 19
Author(s):  
Faaiz Alhamdani ◽  
Khawla H. Rasheed ◽  
Amjed Mahdi

Background: The introduction of modified thread designs is one of the research areas of interest in the dental implantology field. Two suggested Buttress and Reverse Buttress thread designs in TiG5 and TiG4 models are tested against a standard TiG5 Fin Thread design (IBS®). Purpose: The study aims to compare stress distribution around the suggested designs and Fin Thread design. Methods: Three dental implant models: Fin Thread design, and newly suggested Buttress and Reverse Buttress designs of both TiG5 and TiG4 models were tested using FEA for stress distribution using static (70N, 0°) and (400N, 30°) occlusal loads. Results: The main difference between the suggested Buttress design and Fin Thread design lies in the overload (400N, 30°) condition. Maximum Von Mises stress is less in Buttress design than Fin Thread design. On the other hand the level of Von Mises stress over the buccolingual slop of the cancellous bone in Fin Thread design liess within the lowest stress level. The suggested Reverse Buttress design, on the other hand showed almost uniform stress distribution in both TiG4 and TiG4 models with maximum Von Mises stress higher than the elastic modulus of cancellous bone in overload (400N, 30°) condition. Conclusion: The suggested TiG4 Buttress design might have a minor advantage of stress level in cases of stress overload. In contrast, Fin Thread design shows minimal stress over the buccolingual slop of the cancellous bone. The suggested Reverse Buttress design might be more suitable for the D1 bone quality region with the advantage of almost uniform stress distribution


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