scholarly journals The Stability of Hydroxyapatite/Poly-L-Lactide Fixation for Unilateral Angle Fracture of the Mandible Assessed Using a Finite Element Analysis Model

Materials ◽  
2020 ◽  
Vol 13 (1) ◽  
pp. 228 ◽  
Author(s):  
Byungho Park ◽  
Bryan Taekyung Jung ◽  
Won Hyeon Kim ◽  
Jong-Ho Lee ◽  
Bongju Kim ◽  
...  
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Three Dimensional ◽  
Mg Alloy ◽  
Von Mises Stress ◽  
Analysis Model ◽  
Element Analysis ◽  
Angle Fracture ◽  
Von Mises ◽  
The Right

Recently, a hydroxyapatite particle/poly-L-lactide (HA-PLLA) composite device was introduced as an alternative to previous fixation systems. In this study, we used finite element analysis to simulate peak von Mises stress (PVMS) and deformation of bone plates and screws with the following four materials—Ti, Mg alloy, PLLA, and HA-PLLA—at a unilateral mandibular fracture. A three-dimensional virtual mandibular model was constructed, and the fracture surface was designed to run from the left mandibular angle. Masticatory loading was applied on the right first molars. Stress was concentrated at the upper part and the neck of the screw. The largest PVMS was observed for Ti; that was followed by Mg alloy, HA-PLLA, and PLLA. The largest deformation was observed for PLLA; next was HA-PLLA, then Mg alloy, and finally Ti. We could rank relative superiority in terms of mechanical properties. The HA-PLLA screw and mini-plate deformed less than 0.15 mm until 300 N. Thus, we can expect good bone healing with usual masticatory loading six weeks postoperatively. HA-PLLA is more frequently indicated clinically than PLLA owing to less deformation. If the quality of HA-PLLA fixation is improved, it could be widely utilized in facial bone trauma or craniofacial surgery.

scholarly journals Biomechanical assessment of different fixation methods in mandibular high sagittal oblique osteotomy using a three-dimensional finite element analysis model

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Charles Savoldelli ◽  
Elodie Ehrmann ◽  
Yannick Tillier
Keyword(s):  
Finite Element ◽  
Stress Distribution ◽  
Three Dimensional ◽  
Von Mises Stress ◽  
Analysis Model ◽  
Element Analysis ◽  
Fixation Methods ◽  
Oblique Osteotomy ◽  
Von Mises

AbstractWith modern-day technical advances, high sagittal oblique osteotomy (HSOO) of the mandible was recently described as an alternative to bilateral sagittal split osteotomy for the correction of mandibular skeletal deformities. However, neither in vitro nor numerical biomechanical assessments have evaluated the performance of fixation methods in HSOO. The aim of this study was to compare the biomechanical characteristics and stress distribution in bone and osteosynthesis fixations when using different designs and placing configurations, in order to determine a favourable plating method. We established two finite element models of HSOO with advancement (T1) and set-back (T2) movements of the mandible. Six different configurations of fixation of the ramus, progressively loaded by a constant force, were assessed for each model. The von Mises stress distribution in fixations and in bone, and bony segment displacement, were analysed. The lowest mechanical stresses and minimal gradient of displacement between the proximal and distal bony segments were detected in the combined one-third anterior- and posterior-positioned double mini-plate T1 and T2 models. This suggests that the appropriate method to correct mandibular deformities in HSOO surgery is with use of double mini-plates positioned in the anterior one-third and posterior one-third between the bony segments of the ramus.

A comparative study between zirconia and titanium abutments on the stress distribution in parafunctional loading: A 3D finite element analysis

2020 ◽  
Vol 28 (6) ◽  
pp. 603-613 ◽  
Author(s):  
Efe Can Sivrikaya ◽  
Mehmet Sami Guler ◽  
Muhammed Latif Bekci
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Three Dimensional ◽  
Von Mises Stress ◽  
Principal Stresses ◽  
Element Analysis ◽  
Dimensional Finite Element ◽  
3D Fea ◽  
Von Mises ◽  
Three Dimensional Finite Element

BACKGROUND: Zirconia has become a popular biomaterial in dental implant systems because of its biocompatible and aesthetic properties. However, this material is more fragile than titanium so its use is limited. OBJECTIVES: The aim of this study was to compare the stresses on morse taper implant systems under parafunctional loading in different abutment materials using three-dimensional finite element analysis (3D FEA). METHODS: Four different variations were modelled. The models were created according to abutment materials (zirconia or titanium) and loading (1000 MPa vertical or oblique on abutments). The placement of the implants (diameter, 5.0 × 15 mm) were mandibular right first molar. RESULTS: In zirconia abutment models, von Mises stress (VMS) values of implants and abutments were decreased. Maximum and minimum principal stresses and VMS values increased in oblique loading. VMS values were highest in the connection level of the conical abutments in all models. CONCLUSIONS: Using conical zirconia abutments decreases von Mises stress values in abutments and implants. However, these values may exceed the pathological limits in bruxism patients. Therefore, microfractures may be related to the level of the abutment.

Three-Dimensional Modeling and Finite Element Analysis of an Ankle External Fixator

2020 ◽  
Vol 899 ◽  
pp. 94-102
Author(s):  
Nur Faiqa Ismail ◽  
Muhammmad Aiman Firdaus Bin Adnan ◽  
Solehuddin Shuib ◽  
Nik Ahmad Hambali Nik Abd Rashid
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
External Fixator ◽  
Three Dimensional ◽  
Von Mises Stress ◽  
External Fixators ◽  
Element Analysis ◽  
Stress And Deformation ◽  
The Stability ◽  
Von Mises

External fixator has played an important role in repairing fractured ankle bone. This surgery is done due to the several factors which are the bone is not normal position or has broken into several pieces. The external fixator will help the broken bone to grow and remodel back to the original appearance. However, there are some issues regarding to the stability of this fixation. Improper design and material are the major factor that decreased the stability since it is related to the deformation of the external fixator to hold the bone fracture area. This study aims to design a stable structure for constructing delta frame ankle external fixator to increase the stability of the fixation. There are two designs of external fixator with two types of material used in this present study. Both external fixators with different materials are analyzed in terms of von Mises stress and deformation by using a conventional Finite Element Analysis software; ANSYS Workbench V15. The result obtained shows the Model 1 with stainless steel has less stress and deformation distributions compared to the Model 2. Hence, by using Model 1 as the external fixator, the stability of the fixation can be increased.

scholarly journals To Evaluate the Influence of Different Implant Thread Designs on Stress Distribution of Osseointegrated Implant: A Three-Dimensional Finite-Element Analysis Study–An In Vitro Study

2020 ◽  
Vol 08 (01) ◽  
pp. 09-16
Author(s):  
Chhavi Sharma ◽  
Tarun Kalra ◽  
Manjit Kumar ◽  
Ajay Bansal ◽  
Anupreet Kaur Chawla
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Axial Load ◽  
Three Dimensional ◽  
Von Mises Stress ◽  
Element Analysis ◽  
Osseointegrated Implant ◽  
Implant Therapy ◽  
Von Mises ◽  
Selection Of

Abstract Introduction Dental implants are common treatment modality for tooth loss which leads to unaesthetic appearance and may also cause deterioration of mastication and speech. The aim of implant therapy in dentistry is to restore tissue contour, function, comfort, aesthetic, and speech. Dental implant role is to transfer the mechanical force created during chewing to the supporting osseous tissues within the mandible and maxilla. The importance of biomechanical factors such as the bone-implant interface, implant thread design, the length and diameter of implants, type of loading, the quality and quantity of surrounding bone have been strained by various authors. The selection of implant thread design plays an important role in the outcome of the treatment. This study was done to evaluate the influence of different thread designs on stress distribution of osseointegrated implant using three-dimensional (3D) finite-element analysis. Materials and Methods Three implants with different thread designs, namely V-thread, buttress, and reverse buttress thread designs were considered and dimensions were standardized. The site considered was the mandibular molar region with cortical and cancellous bone assuming to be isotropic and homogeneous. The implant modeling was done with the ANSYS 18.1 software. Axial load (100N) and buccolingual load (50N) were applied. The stresses were calculated as Von Mises stress criterion. Results Minimum von mises Stress concentration was seen for tapered implant body with reverse buttress thread design under axial load 100N and tapered implant body with V-thread under buccolingual load of 50N at cortical bone which signifies bone preservation. Stress levels were observed maximum at implant and minimum at the cancellous bone. Conclusion Hence, within the limitations of this study the results obtained can be applied clinically for appropriate selection of implant thread design for a predictable success of implant therapy.

Finite Element Analysis on the Influence of Back-Up Ring on the Sealing Effect of Rubber O-Ring

2011 ◽  
Vol 199-200 ◽  
pp. 1595-1599
Author(s):  
Dian Xin Li ◽  
Hong Lin Zhao ◽  
Shi Min Zhang ◽  
Chang Run Wu ◽  
Xian Long Liu ◽  
...  
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Stress Distribution ◽  
Service Life ◽  
Contact Pressure ◽  
Von Mises Stress ◽  
Analysis Software ◽  
Element Analysis ◽  
Von Mises ◽  
The Right

Based on finite element analysis software ANSYS, the deformation and force condition of the rubber sealing o-ring pre and post with back-up ring under different oil pressure conditions was analyzed. The von mises stress distribution of the o-ring and the change of contact pressure between o-ring and sealing interface pre and post with back-up ring under different oil pressure conditions were discussed. The results show that, the maximum von mises stress of the o-ring is smaller and the maximum von mises stress of the sealing system concentrates on the left top and the right bottom of the back-up ring after using it; the o-ring will not be extruded into the gap of the groove because of the existence of back-up ring which prevents gap-bite and prolongs service life of the o-ring; the contact pressure between o-ring and sealing interface increased, thus the sealing reliability of the system increased.

scholarly journals Finite Element Analysis Comparison of Plate Designs in Managing Fractures Involving the Mental Foramen

2013 ◽  
Vol 6 (2) ◽  
pp. 93-97 ◽  
Author(s):  
Neralla Mahathi ◽  
Emmanuel Azariah ◽  
C. Ravindran
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Three Dimensional ◽  
Mental Foramen ◽  
Stress Generation ◽  
Von Mises Stress ◽  
Element Analysis ◽  
Plate Design ◽  
Von Mises ◽  
Von Mises Stresses

Introduction The aim of the study was to propose an ideal plating design for fractures running through the mental foramen. Methods The study compared three plating designs—two four-hole miniplates, 2 × 2-hole three-dimensional (3D) plate, and modified 2 × 2-hole 3D plate (posterior strut removed)—using finite element analysis. Von Mises stresses generated around the plates and bone were measured, as well as the mobility that is generated between the fracture fragments by applying muscle forces to generate bite force in one test and applying a force of 500 N over the premolars and first molar region in the second test. Results Von Mises stress in bone with miniplates measured 9.24 MPa in test 1 and 131.99 MPa in test 2. The stress with unmodified 3D plates measured 34.9 MPa in test 1 and150.03 MPa in test 2. The stress with modified 3D plates measured 24.98 MPa in test 1 and 150.59 MPa in test 2. Von Mises stress on the plates and screws measured 28.23 MPa, 95.97 MPa, 72.93 MPa in test 1 and 458.63 MPa, 779.01 MPa, 742.39 MPa in test 2 on miniplates, unmodified 3D plates, and modified 3D plates, respectively. The fracture mobility generated in the model with miniplates measured 0.001 mm in test 1 and 0.01 mm in test 2 and 0.007 mm and 0.02 mm in the model with unmodified 3D plates in test 1 and in test 2, respectively. In the model with modified 3D plates, the value was 0.001 mm and 0.01 mm in tests 1 and 2, respectively. Conclusion The ideal plate design is the two-plate technique with minimal stress generation on the bone and the hardware. The modified 3D plate has adequate strength to be used in the region but needs to be studied in detail.

scholarly journals Stress Distribution on the Prosthetic Screws in the All-on-4 Concept: A Three-Dimensional Finite Element Analysis

2020 ◽  
Vol 46 (1) ◽  
pp. 3-12
Author(s):  
Ji-Hyeon Oh ◽  
Young-Seong Kim ◽  
Joong Yeon Lim ◽  
Byung-Ho Choi
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Stress Distribution ◽  
Three Dimensional ◽  
Von Mises Stress ◽  
Element Analysis ◽  
Dimensional Finite Element ◽  
Edentulous Patients ◽  
Von Mises ◽  
Three Dimensional Finite Element

The all-on-4 concept, which is used to rehabilitate edentulous patients, can present with mechanical complications such as screw loosening and fracture. The purpose of this study was to evaluate the stress patterns induced in the prosthetic screws by the different prosthetic screw and abutment designs in the all-on-4 concept using finite element analysis. Von Mises stress values on 6 groups of each screw type, including short and narrow screw, short abutment; short and wide screw, short abutment; long and wide screw, short abutment; short and narrow screw, long abutment; short and wide screw, long abutment; and long and wide screw, long abutment, were compared under a cantilever loading of 200 N that was applied on the farther posterior to the position of the connection between the distal implant and the metal framework. Posterior prosthetic screws showed higher stress values than anterior prosthetic screws. The stress values in posterior prosthetic screws decreased as the length and diameter increased. In conclusion, the long and wide screw design offers advantages in stress distribution when compared with the short and narrow design.

All-on-4 Concept: A 3-Dimensional Finite Element Analysis

2015 ◽  
Vol 41 (2) ◽  
pp. 163-171 ◽  
Author(s):  
Gianpaolo Sannino
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Three Dimensional ◽  
Distribution Patterns ◽  
Von Mises Stress ◽  
Element Analysis ◽  
Biomechanical Behavior ◽  
Dimensional Finite Element ◽  
Von Mises ◽  
Three Dimensional Finite Element

The aim of this work was to study the biomechanical behavior of an All-on-4 implant-supported prosthesis through a finite element analysis comparing 3 different tilt degrees of the distal implants. Three-dimensional finite element models of an edentulous maxilla restored with a prosthesis supported by 4 implants were reconstructed to carry out the analysis. Three distinct configurations, corresponding to 3 tilt degrees of the distal implants (15°, 30°, and 45°) were subjected to 4 loading simulations. The von Mises stresses generated around the implants were localized and quantified for comparison. Negligible differences in von Mises stress values were found in the comparison of the 15° and 30° models. From a stress-level viewpoint, the 45° model was revealed to be the most critical for peri-implant bone. In all the loading simulations, the maximum stress values were always found at the neck of the distal implants. The stress in the distal implants increased in the apical direction as the tilt degree increased. The stress location and distribution patterns were very similar among the evaluated models. The increase in the tilt degree of the distal implants was proportional to the increase in stress concentration. The 45° model induced higher stress values at the bone-implant interface, especially in the distal aspect, than the other 2 models analyzed.

A three-dimensional finite element analysis of resected mandibular bone to determine the most stable implant positions for a fixed prosthesis

2021 ◽  
Author(s):  
Yasufumi Kosugi ◽  
Makoto Hirota ◽  
Naohito Tamai ◽  
Hikaru Takasu ◽  
Toshinori Iwai ◽  
...  
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Three Dimensional ◽  
Von Mises Stress ◽  
Element Analysis ◽  
Bone Stress ◽  
Von Mises ◽  
Three Dimensional Finite Element ◽  
Resected Margin ◽  
Bone Height

This study was conducted to determine the most secure implant positioning on the marginally resected mandible to support a fixed complete denture through finite element analysis. Three or four implants were placed at near, middle, or far positions from the resected margin in a simulation model with a symmetrical marginal defect in the mandibular symphysis. The height of the residual bone was 5, 10, or 15 mm. The four possible implant patterns for 3 or 4 implants were defined as: (1) asymmetrically isolated position one to position two, (2) asymmetrically isolated position one to position three, (3) asymmetrically isolated with greater length position one to position two, and (4) two implants symmetrically positioned on each side of the defect. The von Mises stress in the resected and peri-implant bone with respect to the occlusal force was calculated. Initially, as the peri-implant bone stress around isolated implant at the near position was greater than at the middle and far positions regardless of the residual bone height, the near position was excluded. Second, the von Mises stress in the resected bone region was > 10 MPa when the isolated implant was at the far position, and it increased inversely depending on the bone height. However, the stress was < 10 MPa when the isolated implant was placed at the middle position regardless of the bone height, and it was significantly lower compared to the far position, and equivalent to the symmetrically positioned implants. Furthermore, the use of greater length implant reduced the peri-implant bone stress, which was even lower than that of the symmetrically positioned implants. These results suggest that the asymmetrically positioned three-implant-supported fixed denture, using a greater length isolated implant, placed neither too close to nor too far from the resected margin, can be an effective alternative to the symmetrically positioned four-implant-supported fixed denture.

scholarly journals Effects of Different Fluting Medium Geometries on Von-Mises Stress and Deformation in Single Fluted Board: A Three-Dimensional Finite Element Analysis

2020 ◽  
Author(s):  
Mohd Salahuddin Mohd Basri ◽  
Mohd Zuhair Mohd Nor ◽  
Rosnah Shamsudin ◽  
Intan Syafinaz Mohamed Amin Tawakkal ◽  
Nur Hamizah Abdul Ghani ◽  
...  
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Three Dimensional ◽  
High Strength ◽  
Von Mises Stress ◽  
Element Analysis ◽  
Heavy Product ◽  
Stress And Deformation ◽  
Von Mises ◽  
Three Dimensional Finite Element

Paperboard box produced in large volume for packaging purpose either to pack light or heavy product. When a heavy product is packed, high strength and structural stability against compression and deformation of the paperboard box are demanded. This paper investigates the effects of different shape of fluting mediums on the von Mises stress and deformation using finite element analysis (FEA) tool. Solidworks and ANSYS software were used to design a 3-D model and perform static structural analysis, respectively. The result from the analysis and simulation revealed that common s-shape geometry experienced the lowest von Mises stress and deformation. Honeycomb geometry experienced the highest von Mises stress of 0.19576 MPa while triangle fluting medium recorded the highest deformation at 1.8695E-4mm.

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