scholarly journals Effects of Different Positions and Angles of Implants in Maxillary Edentulous Jaw on Surrounding Bone Stress under Dynamic Loading: A Three-Dimensional Finite Element Analysis

2019 ◽  
Vol 2019 ◽  
pp. 1-9
Author(s):  
Xiaqing Liu ◽  
Fang Pang ◽  
Ying Li ◽  
Hui Jia ◽  
Xiaohua Cui ◽  
...  

Purpose. To evaluate the effects of different placements of mesial implants and different angles of distant implants in maxillary edentulous jaws on the stress on the implant and the surrounding bone tissue under dynamic loading. Materials and Methods. Cone beam computed tomography was used to acquire images of maxillary edentulous jaws. Using Mimics 17.0, Geomagic, and Unigraphics NX8.5 software, three-dimensional models were established: two mesial implants were placed vertically in the anterior region of the maxilla (bilateral central incisor, lateral incisor, and canine), and two distant implants were placed obliquely in the bilateral second premolar area at different inclined angles (15°, 30°, and 45°). The established models were designated I–IX. The models were subjected to dynamic load using Abaqus 6.12, with the working side posterior teeth loading of 150 N and simulation cycle of 0.875 s. Results. During the second to fourth phases of the mastication cycle, the stress was mainly concentrated on the neck of the distal implant. The stress of the distal implants was greater than that of mesial implants. Stress levels peaked in the third stage of the cycle. The stress of the distal cortical bone of distal implant of Model I reached the maximum of 183.437 MPa. The stress of the distal cortical bone and cancellous bone of distal implant of Model VIII represented the minima (62.989 MPa and 17.186 MPa, respectively). Conclusions. Our models showed optimal stress reductions when the mesial implants were located in the canine region and the distal implants tilted 30°.

Author(s):  
Suneetha Rao ◽  
Honey Arora ◽  
Shahul Hameed

ABSTRACT Purpose In spite of many advances in the field of prosthetic dentistry, the choice of whether to treat and retain a grossly compromised tooth or to extract and replace with an implant is debatable. Alveolar bone preservation is one of the main criteria to select the treatment option. This is directly affected by the stress generated in the cortical bone under variable loads and is therefore, relevant. Materials and methods Two three-dimensional finite element models were generated in relation to maxillary second premolar using ANSYS software. Model-I was parallel-tapered titanium implant with screw-retained titanium abutment and porcelain fused to metal (PFM) crown. Model-P was fiber post and com- posite resin core with PFM crown. Luting cement was resin cement. Both the models were surrounded by homogeneous and isotropic cortical and cancellous bone, and were subjected to variable loads of 300, 400, and 500 N in axial (0°) and nonaxial (15°, 45°) directions. Results Stress in the cortical bone in megapascal (MPa) in Model-I/Model-P when subjected to variable loads in newtons(N) in axial direction was 300 N - 37.6 MPa/47.3 MPa; 400 N - 50.2 MPa/63.0 MPa; 500 N - 62.7 MPa/63.0 MPa. 15°- 300 N - 68.5 MPa/65.9 MPa; 400 N - 91.3 MPa/87.9 MPa; 500 N - 114.2 MPa/87.9 MPa. 45° - 300 N - 136.3 MPa/88.9 MPa; 400 N - 181.8 MPa/118.5 MPa; 500 N - 227.2 MPa/118.5 MPa. Conclusion Within the limitation of this study, it was concluded that on axial loading, both the treatment modalities showed no significant difference, but on nonaxial loading, the cortical bone in the implant model showed to have considerably higher stress than post core-treated tooth model. Hence, given a choice, this study favors retaining and restoring a compromised tooth with post core and crown rather than extracting and replacing with an implant. How to cite this article Rao S, Arora H, Hameed S. A Three- dimensional Finite Element Analysis of Stress Distribution in the Cortical Bone in Single Tooth Implant and Post Core-treated Tooth subjected to variable Loads. Int J Prosthodont Restor Dent 2017;7(1):8-16.


Author(s):  
Noureddine Djebbar ◽  
B. Serier ◽  
Bel Abbès Bachir Bouiadjra

Stable osseointegration between implant threads and the surrounding marginal bone provides the mechanical base of an implant for daily chewing activity. The contact area of implant-bone interfaces and the concentrated stresses on the marginal bones are principal concerns of implant designers. In this work we numerically analyze by the finite element method the distribution of the equivalent stress and their level in the bone the most fragile element of the dental prosthesis. Each set of the model contained a crown, framework, abutment, implant and bone, subjected to variable dynamic loading according to time.


Materials ◽  
2021 ◽  
Vol 14 (10) ◽  
pp. 2666
Author(s):  
Jae-Hyun Lee ◽  
Ho Yeol Jang ◽  
Su Young Lee

The present study was designed to compare the stress distributions in two restoration types of implants and the surrounding bone. The first restoration type was a conventional cement-retained zirconia crown, and the second was a novel cementless screw-retained zirconia crown with a base abutment. A three-dimensional finite element method was used to model the implants, restorations, and supporting bone. A comparative study of the two implants was performed under two masticatory loads: a vertical load of 100 N and a 30-degree oblique load of 100 N. Under both loading conditions, the maximum von Mises stress and strain values in the implant and supporting bone were higher in the conventional cement-retained restoration model than in the cementless screw-retained model. In terms of stress distribution, the cementless screw-retained zirconia crown with base abutment may be considered a superior restoration option compared to the conventional cement-retained zirconia crown.


2021 ◽  
Vol 11 (Suppl. 1) ◽  
pp. 194-200
Author(s):  
Yakup Kantaci ◽  
Sabiha Zelal Ülkü

Aim: To evaluate the stress distribution in the cortical bone under parafunctional forces with different occlusal thicknesses, monolithic zirconia with different implant diameters, and number variations in implant-supported fixed prosthetic restorations applied in patients with bruxism. Methodology: The tomographic sections of the previously registered mandible were used in order to model the mandible. Modeled bone height is 30 mm, cortical bone thickness is 1.5 mm, and trabecular bone thickness is modeled as 13 mm. By placing two implants in the created bone model, a three-member main model (Group 1), the number of implants was increased, three implants supported the Group 2 models, the diameter of the implants was increased, and the Group 3 models were created. The created Group 1, 2, 3 models, the occlusal thickness was divided into subgroups with 1.0, 1.5, and 2.0 mm, respectively (Groups A, B, and C). The groups were applied in two directions: vertical and 30o oblique. Stress values under forces were analyzed by finite element stress analysis. Results: Under vertical loading, the maximum principal stress value in the cortical bone was found to be lowest in Group 2C, and the highest maximum principal stress value was found in Group 1A. The minimum principal stress value in the cortical bone was found to be the lowest in Group 3C, and the highest minimum principal stress value was found in Group 1A. Under oblique loading, the maximum principal stress value in the cortical bone was found to be the lowest in Group 3C and the highest maximum principal stress value was found in Group 1A. The minimum principal stress value in the cortical bone was found to be lowest in Group 3C, and the highest minimum principal stress value was found in Group1A. Conclusion: Stresses caused by oblique forces are more than vertical forces. Increasing the occlusal thickness of the implant fixed prosthesis material, implant diameter, and number reduce the minimum and maximum principal stress values in the cortical   How to cite this article: Kantaci Y, Ülkü SZ. Evaluation of the stress distribution in the cortical bone caused by variations in implant applications in patients with bruxism: A three-dimensional finite element analysis. Int Dent Res 2021;11(Suppl.1):194-200. https://doi.org/10.5577/intdentres.2021.vol11.suppl1.27   Linguistic Revision: The English in this manuscript has been checked by at least two professional editors, both native speakers of English.


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