scholarly journals Biomechanical Analysis of Clavicle Hook Plates with a Range of Posterior Hook Offsets Implanted at Different Acromion Positions in the Acromioclavicular Joint: A Finite Element Analysis Study

2021 ◽  
Vol 11 (23) ◽  
pp. 11105
Author(s):  
Li-Kun Hung ◽  
Cheng-Hung Lee ◽  
Kuo-Chih Su

The clavicle hook plate is commonly used in acromioclavicular injuries; however, the biomechanical effect of the posterior hook offset and hook position is unclear. This study applied a finite element analysis (FEA) to evaluate these parameters to improve the clinical strategy. Nine FEA models with 0-mm, 5-mm, and 10-mm posterior hook offsets implanted in the anterior, middle, and posterior acromion were established to evaluate the stress distribution and the reaction force on the acromion. The 5-mm and 10-mm posterior hook offsets at all acromion positions reduced the reaction force on the acromion but slightly increased the stress on the clavicle. The 0-mm offset increased the reaction force at all acromion positions and was relatively lower at the middle acromion. The clavicle hook plate with a posterior hook offset reduces the reaction force on the acromion, providing a flexibility of the hook position. These results provide surgeons with the biomechanical basis for the hook offset and position and engineers with the mechanical basis for the implant design.

2021 ◽  
Vol 11 (6) ◽  
pp. 2547 ◽  
Author(s):  
Carlo Prati ◽  
João Paulo Mendes Tribst ◽  
Amanda Maria de Oliveira Dal Piva ◽  
Alexandre Luiz Souto Borges ◽  
Maurizio Ventre ◽  
...  

The aim of the present investigation was to calculate the stress distribution generated in the root dentine canal during mechanical rotation of five different NiTi endodontic instruments by means of a finite element analysis (FEA). Two conventional alloy NiTi instruments F360 25/04 and F6 Skytaper 25/06, in comparison to three heat treated alloys NiTI Hyflex CM 25/04, Protaper Next 25/06 and One Curve 25/06 were considered and analyzed. The instruments’ flexibility (reaction force) and geometrical features (cross section, conicity) were previously investigated. For each instrument, dentine root canals with two different elastic moduli(18 and 42 GPa) were simulated with defined apical ratios. Ten different CAD instrument models were created and their mechanical behaviors were analyzed by a 3D-FEA. Static structural analyses were performed with a non-failure condition, since a linear elastic behavior was assumed for all components. All the instruments generated a stress area concentration in correspondence to the root canal curvature at approx. 7 mm from the apex. The maximum values were found when instruments were analyzed in the highest elastic modulus dentine canal. Strain and von Mises stress patterns showed a higher concentration in the first part of curved radius of all the instruments. Conventional Ni-Ti endodontic instruments demonstrated higher stress magnitudes, regardless of the conicity of 4% and 6%, and they showed the highest von Mises stress values in sound, as well as in mineralized dentine canals. Heat-treated endodontic instruments with higher flexibility values showed a reduced stress concentration map. Hyflex CM 25/04 displayed the lowest von Mises stress values of, respectively, 35.73 and 44.30 GPa for sound and mineralized dentine. The mechanical behavior of all rotary endodontic instruments was influenced by the different elastic moduli and by the dentine canal rigidity.


2018 ◽  
Vol 23 (5) ◽  
pp. 825-833 ◽  
Author(s):  
Hidetatsu Tanaka ◽  
Go Yamako ◽  
Hiroaki Kurishima ◽  
Shutaro Yamashita ◽  
Yu Mori ◽  
...  

2020 ◽  
Vol 10 (17) ◽  
pp. 5826
Author(s):  
Pei-Ju Lin ◽  
Kuo-Chih Su

A dental implant is currently the most commonly used treatment for patients with lost teeth. There is no biomechanical reference available to study the effect of different occlusion conditions on dental implants with different positions. Therefore, the aim of this study was to conduct a biomechanical analysis of the impact of four common occlusion conditions on the different positions of dental implants using the finite element method. We built a finite element model that included the entire mandible and implanted seven dental implant fixtures. We also applied external force to the position of muscles on the mandible of the superficial masseter, deep masseter, medial pterygoid, anterior temporalis, middle temporalis, and posterior temporalis to simulate the four clenching tasks, namely the incisal clench (INC), intercuspal position (ICP), right unilateral molar clench (RMOL), and right group function (RGF). The main indicators measured in this study were the reaction force on the temporomandibular joint (TMJ) and the fixed top end of the abutment in the dental implant system, and the stress on the mandible and dental implant systems. The results of the study showed that under the occlusion conditions of RMOL, the dental implant system (113.99 MPa) and the entire mandible (46.036 MPa) experienced significantly higher stress, and the reaction force on the fixed-top end of the abutment in the dental implant system (261.09 N) were also stronger. Under the occlusion of ICP, there was a greater reaction force (365.8 N) on the temporomandibular joint. In addition, it was found that the reaction force on the posterior region (26.968 N to 261.09 N) was not necessarily greater than that on the anterior region (28.819 N to 70.431 N). This information can help clinicians and dental implant researchers understand the impact of different chewing forces on the dental implant system at different positions after the implantation.


Materials ◽  
2019 ◽  
Vol 12 (20) ◽  
pp. 3444
Author(s):  
Avram Manea ◽  
Grigore Baciut ◽  
Mihaela Baciut ◽  
Dumitru Pop ◽  
Dan Sorin Comsa ◽  
...  

Background: Once inserted and osseointegrated, dental implants become ankylosed, which makes them immobile with respect to the alveolar bone. The present paper describes the development of a new and original implant design which replicates the 3D physiological mobility of natural teeth. The first phase of the test followed the resistance of the implant to mechanical stress as well as the behavior of the surrounding bone. Modifications to the design were made after the first set of results. In the second stage, mechanical tests in conjunction with finite element analysis were performed to test the improved implant design. Methods: In order to test the new concept, 6 titanium alloy (Ti6Al4V) implants were produced (milling). The implants were fitted into the dynamic testing device. The initial mobility was measured for each implant as well as their mobility after several test cycles. In the second stage, 10 implants with the modified design were produced. The testing protocol included mechanical testing and finite element analysis. Results: The initial testing protocol was applied almost entirely successfully. Premature fracturing of some implants and fitting blocks occurred and the testing protocol was readjusted. The issues in the initial test helped design the final testing protocol and the new implants with improved mechanical performance. Conclusion: The new prototype proved the efficiency of the concept. The initial tests pointed out the need for design improvement and the following tests validated the concept.


Sign in / Sign up

Export Citation Format

Share Document