scholarly journals Influence of Ti-6Al-4V and Ti-15Zr Dental Implants on the Stress in Mandibular Bone A finite element analysis study

2019 ◽  
Vol 56 (2) ◽  
pp. 469-473
Author(s):  
Cosmin Dima ◽  
Doriana Agop-Forna ◽  
Sanziana Butnaru Moldoveanu ◽  
Consuela Norina Forna

The purpose of our study was to analyze the influence of Ti-6Al-4V and Ti-15Zr dental implants, with complex implant designs, on the cortical and trabecular mandibular bone in regards to the stress value and its distribution using finite element analysis. A total of four 3D implant assemblies were modeled, each consisting of implant, abutment, abutment screw, cement layer, and ceramic crown. Implants were modeled with different macrostructure designs with focus on the main thread and microthread design as well as complex geometry details. All implants were inserted in the second molar position in the mandible bone section, consisting of two macro-structures, a 2 mm thick cortical bone and an internal cancellous bone. Results revealed that small variations in the implant design led to a great difference in the stress values and distribution in both cortical and cancellous bone. Our results suggest no major difference between Ti-6Al-4V and Ti-15Zr in regards to the material�s ability to decrease stress in the periimplant bone. However, within the same material, results revealed important differences between thread design and implant geometry concerning the stress values and stress concentration in cortical and cancellous bone in the mandibular model.

2020 ◽  
Vol 9 (3) ◽  
pp. 621
Author(s):  
Pooyan Rahmanivahid ◽  
Milad Heidari

Nowadays, root osseointegrated dental implants are used widely in dentistry mainly for replacement of the single missing tooth. The success rate of osseointegrated dental implants depends on different factors such as bone conditions; surgery insertion technique, loading history, and biomechanical interaction between jawbone and implant surface. In recent years, many studies have investigated design factors using finite element analysis with a concentration on major parameters such as diameter, pitch, and implant outlines in the distribution of stress in the bone-implant interface. There is still a need to understand the relationship and interaction of design factors individually with stress distribution to optimize implant structure. Therefore, the present study introduced a new dental implant and investigated the effect of design parameters on stress distribution. The finite element modeling was developed to facilitate the study with a comparison of design parameters. Boundary and loading conditions were implemented to simulate the natural situation of occlusal forces. Based on results, V-shape threads with maximum apex angle caused a high rate of micro-motion and high possibility of bone fracture. Low Von-Mises stress was associated with low bone growth stimulation. Besides, small fin threads did not integrate with cancellous bone and consequently lower stress accommodation. V-5 fin had no extraordinary performance in cancellous bone. Small surface areas of fins did not integrate with the surrounding bone and high-stress concentration occurred at the tail. These fins are recommended as threads replacement. It was concluded that the implant structure had less influence on stress distribution under horizontal loading.  


2011 ◽  
Vol 83 ◽  
pp. 73-77 ◽  
Author(s):  
Yasuyuki Morita ◽  
Yasuyuki Matsushita ◽  
Mitsugu Todo ◽  
Kiyoshi Koyano

For normal healthy teeth, the percussive energy generated by mastication is attenuated by the periodontal ligament at the healthy bone/natural tooth interface. However, when a natural tooth must be replaced by an implant because of damage or disease, the ligament is lost and the implant will transmit the percussive forces to the bone directly. Studies have evaluated the deformation distribution of the alveolar bone in the vicinity of implants using finite element analysis and photoelasticity. However, finite element analysis requires clinical verification or a determination of material properties, and photoelastic materials generally have material properties and structure quite different from those of actual bone. Therefore, this study examined the deformation distribution around dental implants in cortical/cancellous bone experimentally using sawbone cortical/cancellous bone models. Dental implants were placed in the bone models and the displacement distribution was measured using the digital image correlation method, and the strain distribution was visualized under a compressive load that simulated the occlusion force.


2021 ◽  
Vol 11 (3) ◽  
pp. 1220
Author(s):  
Azeem Ul Yaqin Syed ◽  
Dinesh Rokaya ◽  
Shirin Shahrbaf ◽  
Nicolas Martin

The effect of a restored machined hybrid dental ceramic crown–tooth complex is not well understood. This study was conducted to determine the effect of the stress state of the machined hybrid dental ceramic crown using three-dimensional finite element analysis. Human premolars were prepared to receive full coverage crowns and restored with machined hybrid dental ceramic crowns using the resin cement. Then, the teeth were digitized using micro-computed tomography and the teeth were scanned with an optical intraoral scanner using an intraoral scanner. Three-dimensional digital models were generated using an interactive image processing software for the restored tooth complex. The generated models were imported into a finite element analysis software with all degrees of freedom concentrated on the outer surface of the root of the crown–tooth complex. To simulate average occlusal load subjected on a premolar a total load of 300 N was applied, 150 N at a buccal incline of the palatal cusp, and palatal incline of the buccal cusp. The von Mises stresses were calculated for the crown–tooth complex under simulated load application was determined. Three-dimensional finite element analysis showed that the stress distribution was more in the dentine and least in the cement. For the cement layer, the stresses were more concentrated on the buccal cusp tip. In dentine, stress was more on the cusp tips and coronal 1/3 of the root surface. The conventional crown preparation is a suitable option for machined polymer crowns with less stress distribution within the crown–tooth complex and can be a good aesthetic replacement in the posterior region. Enamic crowns are a good viable option in the posterior region.


Author(s):  
Luiz Bassi Junior ◽  
Rafael Oliveira de Souza Silva ◽  
Victor Hugo Dias dos Santos ◽  
Abner da Rocha Lourenço ◽  
Paulo Vinicius Trevizoli ◽  
...  

2020 ◽  
Vol 2020 ◽  
pp. 1-19
Author(s):  
Mashallah Khanehmasjedi ◽  
Sepideh Bagheri ◽  
Vahid Rakhshan ◽  
Mojtaba Hasani

Introduction. Miniscrews have proved quite effective in fixed orthodontic treatment. They can be placed in areas like palatal interradicular zones or midpalatal suture. Despite the value of these methods and their ever-increasing use, their characteristics are not assessed before when implanted in palatal interradicular areas or in the midpalatal suture. We aimed to assess, for the first time, the dynamics of full arch distalization using such miniscrews. Methods. A 3D model of maxilla with all permanent dentition was created from a CT scan volume. Tissues were segmented and differentiated. Afterward, miniscrews and appliances were designed, and the whole model was registered within a finite element analysis software by assigning proper mechanical properties to tissues and orthodontic appliances. The full arches were distalized using transpalatal arches with miniscrews as anchorage devices (in two different models). The extents of stresses and patterns of movements of various elements (teeth, miniscrews, appliances, tissues) were estimated. Results and Conclusions. Comparing the two models, it is obvious that in both models, the stress distribution is the highest in the TPA arms and the head of the miniscrew where the spring is connected. In comparison with the displacement in the X-axis, the “mesial in” rotation is seen in the first molar of both models. But there is one exception and that is the “mesial out” rotation of the right second molar. In all measurements, the amount of movement in Model 2 (with palatal interradicular miniscrews) is more than that in Model 1 (with midpalatal miniscrew). In the Y-axis, more tipping is seen in Model 2, especially the anterior teeth (detorque) and the first molar, but in Model 1, bodily movement of the first molar is more evident. Along the Z-axis, the mesial intrusion of the first molar and the distal extrusion of this tooth can be seen in both models. Again, the displacement values are higher in the second model (with interradicular miniscrews). In comparison with micromotion and stress distribution of miniscrews, in Model 1, maximum stress and micromotion is observed at the head of the miniscrew where it is attached to the spring. Of course, this amount of micromotion increases over time. The same is true for Model 2, but with a lower micromotion. As for the amount of stress, the stress distribution in both miniscrews of both models is almost uniform and rather severe.


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