Evaluation of different force magnitude to orthodontic microimplants on various cortical bone thickness – Three-dimensional finite element analysis

2019 ◽  
Vol 10 (2) ◽  
pp. 65
Author(s):  
Akash Kencha ◽  
BC Patil ◽  
Spoorthy Obalapura ◽  
Vishwanath Patil ◽  
Kasturi Patil
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.


2015 ◽  
Vol 09 (03) ◽  
pp. 311-318 ◽  
Author(s):  
Ebadian Behnaz ◽  
Mosharraf Ramin ◽  
Samaneh Abbasi ◽  
Memar Ardestani Pouya ◽  
Farzin Mahmood

ABSTRACT Objective: The aim of this study was to investigate the influence of implant crown splinting and the use of angulated abutment on stress distribution in implant body and surrounding bone by three-dimensional finite element analysis. Materials and Methods: For this study, three models with two implants at the site of mandibular right second premolar and first molar were designed (1): Both implants, parallel to adjacent teeth, with straight abutments (2): Anterior implant with 15 mesial angulations and posterior implant were placed parallel to adjacent tooth, (3): Both implants with 15 mesial angulations and parallel to each other with 15° angulated abutments. Restorations were modeled in two shapes (splinted and nonsplinted). Loading in tripod manner as each point 50 N and totally 300 N was applied. Stress distribution in relation to splinting or nonsplinting restorations and angulations was done with ABAQUS6.13. Results: Splinting the restorations in all situations, led to lower stresses in all implant bodies, cortical bone and spongy bone except for the spongy bone around angulated first molar. Angulated implant in nonsplinted restoration cause lower stresses in implant body and bone but in splinted models more stresses were seen in implant body in comparison with straight abutment (model 2). Stresses in nonsplinted and splinted restorations in cortical bone of angulated molar region were more than what was observed in straight molar implant (model 3). Conclusion: Implant restorations splinting lead to a better distribution of stresses in implant bodies and bone in comparison with nonsplinted restorations, especially when the load is applied off center to implant body. Angulations of implant can reduce stresses when the application of the load is in the same direction as the implant angulation.


2004 ◽  
Vol 19 (1) ◽  
pp. 114-123 ◽  
Author(s):  
Z. Fan ◽  
J.Y. Rho ◽  
J.G. Swadener

A three-dimensional finite element analysis (FEA) model with elastic–plastic anisotropy was built to investigate the effects of anisotropy on nanoindentation measurements for cortical bone. The FEA model has demonstrated a capability to capture the cortical bone material response under the indentation process. By comparison with the contact area obtained from monitoring the contact profile in FEA simulations, the Oliver–Pharr method was found to underpredict or overpredict the contact area due to the effects of anisotropy. The amount of error (less than 10% for cortical bone) depended on the indentation orientation. The indentation modulus results obtained from FEA simulations at different surface orientations showed a trend similar to experimental results and were also similar to moduli calculated from a mathematical model. The Oliver–Pharr method has been shown to be useful for providing first-order approximations in the analysis of anisotropic mechanical properties of cortical bone, although the indentation modulus is influenced by anisotropy.


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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