scholarly journals Bone Loss in Bruxist Patients Wearing Dental Implant Prostheses: A Finite Element Analysis

Metals ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 1132
Author(s):  
Luis-Guillermo Oliveros-López ◽  
Raquel Castillo-de-Oyagüe ◽  
María-Ángeles Serrera-Figallo ◽  
Álvaro-José Martínez-González ◽  
Andrea Pérez-Velasco ◽  
...  

Bruxism is an unconscious, involuntary and sustained motor activity that results in excessive teeth grinding or jaw clenching that could affect patients’ implants and rehabilitations. The aetiology for bruxism remains unknown, but it is known to involve multiple factors. The literature lacks studies on the possible effect of implant morphology on the resistance of the bone-implant osseointegrated interface when bruxism is present. Our objective is to assess the mechanical response of the bone-implant interface in bruxist patients whose implant prostheses are subjected to parafunctional cyclic loading over a simulated period of 10 years. A comparison was carried out between two implant types (M-12 and Astra Tech), and a pattern of bone loss was established considering both the stress state and the cortical bone surface loss as the evaluation criteria. Numerical simulation techniques based on the finite element analysis method were applied in a dynamic analysis of the received forces, together with a constitutive model of bone remodelling that alters the physical properties of the bone. The simulated cortical bone surface loss at the implant neck area was 8.6% greater in the Astra implant than in the M-12 implant. Compared to the M-12 implant, the higher sustained stress observed over time in the Astra implant, together with the greater cortical bone surface loss that occurred at its neck area, may be related to the major probability of failure of the prostheses placed over Astra implants in bruxist patients.

2021 ◽  
Vol 15 (4) ◽  
pp. 262-268
Author(s):  
Omar Nazal Auwer ◽  
Marwa Sameh Shamaa ◽  
Shaza Mohammad Hammad

Background. The present study aimed to assess the stress and strain distribution on mini-screws and the surrounding bone in cases of different cortical bone thicknesses (CBTs), mini-screw insertion angles, and force directions using finite element analysis (FEA). Methods. Inventor professional version 8 software was used to construct 24 three-dimensional assemblies of mini-screws inserted with different insertion angles (30º, 60º, and 90º) in alveolar bone blocks with different CBTs (0.5, 1, 1.5, and 2 mm). The models simulated mini-screws inserted in bones with different CBTs and different insertion angles. A 2-N load was applied in two directions to mini-screw heads. The resultant stresses of the applied load were collected from the output of the ANSYS program. Results. The results indicated that force direction affected bone strains as the horizontal force generated more strains on cortical bone than the oblique one. Force applied to 60º inserted mini-screws generated much more strains on cortical bone than 90º and 30º inserted mini-screws. In a 60º inserted mini-screw, the horizontal force generated about 45% more strains on cortical bone than the oblique one. The exerted microstrain on bone decreased as CBT increased. Conclusion. It can be concluded that inserting mini-screws at 60º to the bone surface should be avoided as it generates much more strains on cortical bone than 90º and 30º, especially when a force parallel to the bone surface is applied.


2008 ◽  
Author(s):  
Serena Bonaretti ◽  
Nils Reimers ◽  
Mauricio Reyes ◽  
Andrei Nikitsin ◽  
Anders Joensson ◽  
...  

We present a framework for statistical finite element analysis allowing performing statistical statements of biomechanical performance of peri-articular implants across a given population. In this paper, we focus on the design of orthopaedic implants that fit a maximum percentage of the target population, both in terms of geometry and biomechanical stability. CT scans of the bone under consideration are registered non-rigidly to obtain correspondences in position between them. A statistical model of shape is computed by means of principal component analysis. A method to automatically propagate standardize fractures on the statistically-based bone population has been developed as well as tools to optimize implant position to best-fit the bone surface. Afterwards, finite element analysis is performed to analyse the biomechanical performance of the bone/implant construct. The mechanical behaviour of different PCA bone instances is compared for tibia representing the Asian and Caucasian populations.


2021 ◽  
Vol 24 (2) ◽  
Author(s):  
Tarcisio José de Arruda Paes Junior ◽  
João Paulo Mendes Tribst ◽  
Amanda Maria de Oliveira Dal Piva ◽  
Viviane Maria Gonçalves de Figueiredo ◽  
Alexandre Luiz Souto Borges ◽  
...  

Purpose: To evaluate the effect of fibromucosa height on the stress distribution and displacement of mandibular total prostheses during posterior unilateral load, posterior bilateral load and anterior guidance using the finite element analysis (FEA). Material and methods: 3D virtual models were made to simulate the stress generated during different mandibular movements in a total prosthesis. The contacts were simulated according to the physiology, being considered perfectly bonded between cortical and medullar bones; and between cortical bone and mucosa. Non-linear frictional contact was used for the total prosthesis base and fibromucosa, allowing the prosthesis to slide over the tissue. The cortical bone base was fixed and the 100 N load was applied as unilateral load, posterior bilateral load and anterior guidance simulation. The required results were for maximum principal stress (MPa), microstrain (mm/mm) and total displacement (mm). The numerical results were converted into colorimetric maps and arranged according to corresponding scales. Results: The stress generated in all situations was directly proportional to the fibromucosa height. The maximum principal stress results demonstrated greater magnitude for anterior guidance, posterior unilateral and posterior bilateral, respectively. Only posterior unilateral load demonstrated an increase in bone microstrain, regardless of the fibromucosa height. Prosthesis displacement was lower under posterior bilateral loading. Conclusion: Posterior bilateral loading is indicated for total prosthesis because it allows lower prosthesis displacement, lower stress concentration at the base of the prosthesis and less bone microstrain.   Keywords Finite element analysis; Occlusion; Total prosthesis.


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