scholarly journals Influence of Abutment Collar Height and Implant Length on Stress Distribution in Single Crowns

2019 ◽  
Vol 30 (3) ◽  
pp. 238-243
Author(s):  
Dimorvan Bordin ◽  
Altair Antoninha Del Bel Cury ◽  
Fernanda Faot
Keyword(s):  
Stress Distribution ◽  
Cortical Bone ◽  
Cancellous Bone ◽  
Stress Reduction ◽  
Von Mises Stress ◽  
Shear Stresses ◽  
Biomechanical Behavior ◽  
In Silico Study ◽  
Von Mises ◽  
Implant Length

Abstract This in silico study evaluated the influence of the abutment collar height and implants length on the biomechanical behavior of morse taper single dental implants with different crown-to-implant ratio. Six virtual models were constructed (S11, M11, L11, S13, M13 and L13) by combining short (S: 2.5 mm), medium (M: 3.5 mm) or long (L: 4.5 mm) abutment collar heights with different implant lengths (11 or 13-mm). An upper central incisor of 11-mm height was constructed on top of each abutment. Each set was positioned in a virtual bone model and exported to analyze mathematically. A 0.60-mm mesh was created after convergence analysis and a 49 N load was applied to the cingulum of the crown at an angle of 45°. Load-generated stress distribution was analyzed in the prosthetic components according to von Mises stress criteria (σvM) and in the cortical and cancellous bone by means of shear stress (εmax). The use of longer collar abutments (L11) increased the stress on the abutment by 250% and resulted in 40% higher stresses on the screw and 92% higher cortical shear stresses compared to short collared abutments (S11). Increasing the implant length produced a slight stress reduction on cortical bone. Cancellous bone was not affected by the crown-to-implant ratio. Longer abutment collars concentrate stresses at the implant level and cortical bone by increasing the crown-to-implant ratio.

Implant Biomechanics in Grafted Sinus: A Finite Element Analysis

2004 ◽  
Vol 30 (2) ◽  
pp. 59-68 ◽  
Author(s):  
Mete I. Fanuscu ◽  
Hung V. Vu ◽  
Bernard Poncelet
Keyword(s):  
Finite Element ◽  
Stress Distribution ◽  
Cortical Bone ◽  
Cancellous Bone ◽  
Stress Reduction ◽  
Lateral Loading ◽  
Von Mises Stress ◽  
Finite Element Models ◽  
Native Bone ◽  
Clinical Scenarios

Abstract This in vitro study investigated the stress distribution in the bone surrounding an implant that is placed in a posterior edentulous maxilla with a sinus graft. The standard threaded implant and anatomy of the crestal cortical bone, cancellous bone, sinus floor cortical bone, and grafted bone were represented in the 3-dimensional finite element models. The thickness of the crestal cortical bone and stiffness of the graft were varied in the models to simulate different clinical scenarios, representing variation in the anatomy and graft quality. Axial and lateral loads were considered and the stresses developed in the supporting structures were analyzed. The finite element models showed different stress patterns associated with helical threads. The von Mises stress distribution indicated that stress was maximal around the top of the implant with varying intensities in both loading cases. The stress was highest in the cortical bone, lower in the grafted bone, and lowest in the cancellous bone. When the stiffness of the grafted bone approximated the cortical bone, axial loading resulted in stress reduction in all the native bone layers; however, lateral loading produced stress reduction in only the cancellous bone. When the stiffness of the graft was less than that of the cancellous bone, the graft assumed a lesser proportion of axial loads. Thus, it caused a concomitant stress increase in all the native bones, whereas this phenomenon was observed in only the cancellous bone with lateral loading. The crestal cortical bone, though receiving the highest intensity stresses, affected the overall stress distribution less than the grafted bone. The stress from the lateral load was up to 11 times higher than that of the axial load around the implant. These findings suggest that the type of loading affects the load distribution more than the variations in bone, and native bone is the primary supporting structure.

Examination of the Stress Distribution in the Tip of a Pencil

2005 ◽  
Vol 73 (2) ◽  
pp. 335-337
Author(s):  
E. Pogozelski ◽  
D. Cole ◽  
M. Wesley
Keyword(s):  
Stress Distribution ◽  
Fracture Surface ◽  
Initial Position ◽  
Von Mises Stress ◽  
Shear Stresses ◽  
Worst Case ◽  
Position And Orientation ◽  
Von Mises ◽  
The Impact ◽  
Normal And Shear Stresses

The stresses within the tip of a pencil are examined theoretically, numerically, and experimentally to determine the position and orientation of the fracture surface. The von Mises stress is used to evaluate the impact of the normal and shear stresses due to compression, bending, torsion, and shear. The worst-case stress is shown to occur along the top edge of the inclined pencil point, where the normal stress is compressive. The resulting crack propagates diagonally downwards and towards the tip from this initial position, and is frequently observed to contain a cusp.

Stress Distribution Around Two Dental Implant Materials with New Designs: Comparative Finite Element Analysis Study

2021 ◽  
Vol 4 (1) ◽  
pp. 19
Author(s):  
Faaiz Alhamdani ◽  
Khawla H. Rasheed ◽  
Amjed Mahdi
Keyword(s):  
Stress Distribution ◽  
Dental Implant ◽  
Cancellous Bone ◽  
Stress Level ◽  
The Other ◽  
Von Mises Stress ◽  
Uniform Stress ◽  
Element Analysis ◽  
Other Hand ◽  
Von Mises

Background: The introduction of modified thread designs is one of the research areas of interest in the dental implantology field. Two suggested Buttress and Reverse Buttress thread designs in TiG5 and TiG4 models are tested against a standard TiG5 Fin Thread design (IBS®). Purpose: The study aims to compare stress distribution around the suggested designs and Fin Thread design. Methods: Three dental implant models: Fin Thread design, and newly suggested Buttress and Reverse Buttress designs of both TiG5 and TiG4 models were tested using FEA for stress distribution using static (70N, 0°) and (400N, 30°) occlusal loads. Results: The main difference between the suggested Buttress design and Fin Thread design lies in the overload (400N, 30°) condition. Maximum Von Mises stress is less in Buttress design than Fin Thread design. On the other hand the level of Von Mises stress over the buccolingual slop of the cancellous bone in Fin Thread design liess within the lowest stress level. The suggested Reverse Buttress design, on the other hand showed almost uniform stress distribution in both TiG4 and TiG4 models with maximum Von Mises stress higher than the elastic modulus of cancellous bone in overload (400N, 30°) condition. Conclusion: The suggested TiG4 Buttress design might have a minor advantage of stress level in cases of stress overload. In contrast, Fin Thread design shows minimal stress over the buccolingual slop of the cancellous bone. The suggested Reverse Buttress design might be more suitable for the D1 bone quality region with the advantage of almost uniform stress distribution

scholarly journals Evaluation of the Effect of Complete and Partial Osseointegration in Stress Development at Bone-Implant Interface: A 3D Finite Element Study

2016 ◽  
Vol 6 (2) ◽  
pp. 24-27
Author(s):  
Bashu Raj Pandey ◽  
Hemant Kumar Halwai ◽  
Khushbu Adhikari ◽  
Amresh Thakur
Keyword(s):  
Finite Element ◽  
Cortical Bone ◽  
Cancellous Bone ◽  
Element Model ◽  
Von Mises Stress ◽  
Element Analysis ◽  
Bone Implant ◽  
Stress Development ◽  
Bone Segment ◽  
Von Mises

Introduction: Mini-implant has been in use as temporary anchorage device in orthodontics. Various factors like length, type of osseointegration, magnitude and direction of force, insertion angle of the mini-implant affect the stress development at the bone and implant interface. Development of undesirable stress at the bone-implant interface can lead to bone defect and failure of the implant. Various opinions regarding the need of osseointegration have been reported.Objective: To study the effect of complete and partial osseointegration on Von Mises stress distribution at the bone-implant interface.Materials & Method: Finite element model of 9mm × 1.5mm mini-implant and bone segment of 1.5mm were constructed to simulate the biomechanical response of the bone to the mini- implant by using CATIA V5-6R 2013 software. Stress developed on implant and bone were analyzed by using ANSYS: 13 2013 version software for both complete and partial level of osseointegration.Result: Maximum Von Mises stress in complete osseointegration was 14.49 Mpa in cortical bone, 0.551 Mpa in cancellous bone and 50.76 Mpa in implant. In partial osseointegration, it was 18.68 Mpa in cortical bone, 1.23 Mpa in cancellous bone and 66.80 Mpa in mini-implant.Conclusion: In partial osseointegration, stress developed was higher but well below the yield strength of respected continuum. So the partial osseointegration is a good compromise between the necessity of reducing mobility of implant and the necessity for easier screw removal. Key words: cancellous bone, cortical bone, Finite element analysis, mini-implant, Von Mises stress

scholarly journals The Effect of Framework Design on Stress Distribution in Implant-Supported FPDs: A 3-D FEM Study

2010 ◽  
Vol 04 (04) ◽  
pp. 374-382 ◽  
Author(s):  
Oguz Eraslan ◽  
Ozgur Inan ◽  
Asli Secilmis
Keyword(s):  
Finite Element ◽  
Stress Concentration ◽  
Stress Distribution ◽  
Bone Structure ◽  
Von Mises Stress ◽  
Stress Concentrations ◽  
Biomechanical Behavior ◽  
Framework Design ◽  
Occlusal Surfaces ◽  
Von Mises

Objectives: The biomechanical behavior of the superstructure plays an important role in the functional longevity of dental implants. However, information about the influence of framework design on stresses transmitted to the implants and supporting tissues is limited. The purpose of this study was to evaluate the effects of framework designs on stress distribution at the supporting bone and supporting implants.Methods: In this study, the three-dimensional (3D) finite element stress analysis method was used. Three types of 3D mathematical models simulating three different framework designs for implant- supported 3-unit posterior fixed partial dentures were prepared with supporting structures. Convex (1), concave (2), and conventional (3) pontic framework designs were simulated. A 300-N static vertical occlusal load was applied on the node at the center of occlusal surface of the pontic to calculate the stress distributions. As a second condition, frameworks were directly loaded to evaluate the effect of the framework design clearly. The Solidworks/Cosmosworks structural analysis programs were used for finite element modeling/analysis.Results: The analysis of the von Mises stress values revealed that maximum stress concentrations were located at the loading areas for all models. The pontic side marginal edges of restorations and the necks of implants were other stress concentration regions. There was no clear difference among models when the restorations were loaded at occlusal surfaces. When the veneering porcelain was removed, and load was applied directly to the framework, there was a clear increase in stress concentration with a concave design on supporting implants and bone structure.Conclusions: The present study showed that the use of a concave design in the pontic frameworks of fixed partial dentures increases the von Mises stress levels on implant abutments and supporting bone structure. However, the veneering porcelain element reduces the effect of the framework and compensates for design weaknesses. (Eur J Dent 2010;4:374-382)

scholarly journals Three-dimensional finite element analysis of mandibular overdentures with different implant positions and attachment types

2018 ◽  
Vol 32 (4) ◽  
pp. 185
Author(s):  
Josué Ricardo Broilo ◽  
Evandro Afonso Sartori ◽  
Luiz Oscar Honorato Mariano ◽  
Leandro Corso ◽  
Rosemary Sadami Arai Shinkai
Keyword(s):  
Finite Element ◽  
Stress Distribution ◽  
Three Dimensional ◽  
Von Mises Stress ◽  
Element Analysis ◽  
Implant Position ◽  
Biomechanical Behavior ◽  
Von Mises ◽  
Three Dimensional Finite Element ◽  
Standard Implant

OBJECTIVE: This 3-D FEA study compared the stress distribution in two-implant mandibular overdentures as a function of implant position and attachment system (LA: locator attachment vs. BA: ball attachment).METHODS: Four models of mandibular overdentures were tested: M1-LA – with implants at the canine regions (standard implant position) and LA; M2-LA – with implants placed at the first premolar regions (distalized implant position) and LA; M1-BA – with standard implant position and BA; and M2-BA – with distalized implant position and BA. The geometric models were converted into finite element models. A 100 N axial load was applied at the first molar region. The von-Mises stress distribution was compared in selected points.RESULTS: The models with BA had pattern of stress distribution was more uniform along the implant axis than the ones with LA, although the stress magnitude was larger. The largest area of von Mises stresses on the alveolar ridge was in the models with standard implant distribution.CONCLUSION: The findings showed that the models with BA had better biomechanical behavior than the ones with LA. For both types of attachment, the models with increased inter-implant distance presented a smaller area of stress distribution in the perimplant cortical bone tissue than the standard implant position. 

DYNAMIC STRESS DISTRIBUTION IN A MODEL OF IMPLANTED MANDIBLE: NUMERICAL ANALYSIS OF VISCOELASTIC BONE

2015 ◽  
Vol 15 (04) ◽  
pp. 1550050 ◽  
Author(s):  
H. MOTALLEBZADEH ◽  
M. TAFAZZOLI-SHADPOUR ◽  
M. M. KHANI
Keyword(s):  
Finite Element ◽  
Stress Distribution ◽  
Cortical Bone ◽  
Dynamic Loading ◽  
Viscoelastic Behavior ◽  
Element Model ◽  
Von Mises Stress ◽  
Dental Implantation ◽  
Trabecular Bones ◽  
Von Mises

To determine the success of dental implants, mechanical stress distribution in the implant-bone interface is considered to be a determinant. Many researchers have used finite element modeling of implant-bone through applying static loading on the implant; however, dynamic loading has not extensively been investigated specially considering viscoelastic behavior of the bone. The aim of this study is to analyze effects of viscoelasticity of bone and dynamic loading comparable to mastication conditions on stress distribution in an implanted mandible. A three-dimensional finite-element model of an implanted mandible in the first molar region was constructed from computerized tomography data. Effects of several parameters, such as material properties including viscoelastic behavior of the cortical and trabecular bones, load amplitude, duration and direction on the instantaneous and long-term von Mises stress distribution of an implanted mandible were evaluated. In all loading conditions, the maximum von Mises stress occurred in cortical bone surrounding the neck of implant. Stress distribution was not noticeably affected by viscoelastic behavior during the first loading cycles, however, after 100 s periodic loading, the differences between stress magnitudes (especially in the cortical bone) became noticeable. In addition, sensitivity analysis showed that both cortical and trabecular bones were more sensitive to axial load than buccalingual and mesiodistal forces. The results of this study contribute to analysis of parameters involved in success of dental implantation.

scholarly journals Optimizing Cement Distribution in the Fractured Area for Osteoporotic Vertebral Compression Fractures Through Biomechanical Effects Analysis Based on a Three Dimentional Lumbar Finite Element Modeling

2020 ◽  
Author(s):  
Lin-qiang Ye ◽  
De Liang ◽  
Zhen Li ◽  
Rui Weng ◽  
Xue-cheng Huang ◽  
...  
Keyword(s):  
Finite Element ◽  
Cortical Bone ◽  
Cancellous Bone ◽  
Von Mises Stress ◽  
Vertebral Compression Fractures ◽  
Osteoporotic Vertebral Compression Fractures ◽  
Maximum Displacement ◽  
Compression Fractures ◽  
Cement Distribution ◽  
Von Mises

Abstract Background: While cement distributes sufficiently in the fractured area and relatively symmetrically around the fractured area, three types of cement mass location in the vertebral body are commonly seen when performing bipedicular percutaneous vertebral augmentation (PVA) for osteoporotic vertebral compression fractures (OVCFs), including anterolateral (AL), anteromedial (AM) and posterolateral (PL). However, little is known about differences of biomechanical behaviors among these three types of cement distribution so far. The present study aimed to investigate biomechanical effects of AL, AM and PL in the fractured area on OVCFs.Methods: Three dimentional finite element methods were utilized to construct OVCF model and simulate AL, AM and PL in the fractured area for OVCFs treated with PVA. Distributions and magnitudes of von Mises stress in cortical and cancellous bone and maximum displacement of the four models were compared.Results: Compared with the OVCF model, Distribution of von Mises stress in cortical bone was unchanged while that in cancellous bone was transferred to be concentrated symmetrically at cancellous bone surrounding cement after PVA. Maximum displacement and maximum von Mises stress in cortical bone in AL decreased the most significantly, while AM created the lowest maximum von Mises stress in cancellous bone.Conclusions: Cement distribution between AL and AM may balance stress in cortical and cancellous bone, better restoring vertebral strength, meanwhile, providing sufficient vertebral stability.

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

2018 ◽  
Vol 6 (02/03) ◽  
pp. 097-105
Author(s):  
Neha Jindal ◽  
Manjit Kumar ◽  
Shailesh Jain ◽  
Navjot Kaur ◽  
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Stress Distribution ◽  
Biomechanical Analysis ◽  
Von Mises Stress ◽  
Element Analysis ◽  
Von Mises ◽  
The Impact ◽  
Implant Length ◽  
Nonsignificant Decrease

AbstractFinite element analysis is a technique for obtaining a solution to a complex mechanical problem by dividing the problem domain into a collection of much smaller and simpler domains (elements) in which the field variables can be interpolated with the use of shape functions. An overall approximated solution to the original problem is determined based on variational principles. Finite element analysis can provide a nondestructive system for quantifying stresses generated at the various interfaces of similar or dissimilar material. The finite element method also allows the study of the internal state of stress of components as well as stress patterns in two or more dissimilar materials adjacent to each other without affecting their independent behavior. This method is therefore ideally suitable for the biomechanical analysis of orthopedic, cardiovascular, and dental structures. In this study, implants of different length were numerically analyzed using bone-implant models developed from computed tomography-generated images of the mandible with osseointegrated implants. The impact of various lengths on stress distribution was examined using implants with a length of 8, 10, and 13 mm in mandibular first molar region under axial load of 100 N and buccolingual load of 50 N. All materials were assumed to be linearly elastic and isotropic. The Statistical Package for the Social Sciences software package was used for statistical analysis. Maximum von Mises stresses were located around the implant neck. It was demonstrated that there was statistically nonsignificant decrease in von Mises stress as the implant length increased. Within the limitations of this study, there was statistically nonsignificant decrease in von Mises stress as the implant length increased.

scholarly journals Biomechanical effect of intertrochanteric curved varus osteotomy on stress reduction in femoral head osteonecrosis: a finite element analysis

2021 ◽  
Vol 16 (1) ◽  
Author(s):  
Yuzhu Wang ◽  
Go Yamako ◽  
Takato Okada ◽  
Hideki Arakawa ◽  
Yoshihiro Nakamura ◽  
...  
Keyword(s):  
Finite Element ◽  
Stress Distribution ◽  
Stress Reduction ◽  
Weight Bearing ◽  
Von Mises Stress ◽  
Type B ◽  
Necrotic Bone ◽  
Element Analysis ◽  
Varus Osteotomy ◽  
Von Mises

Abstract Background Intertrochanteric curved varus osteotomy (CVO) has been widely used to remove the necrotic bone away from the weight-bearing portion in the treatment of osteonecrosis of the femoral head (ONFH). However, whether all types of necrosis will benefit from CVO, in terms of the stress level, the effect of different center-edge (CE) angles of acetabulum on stress distribution of necrosis after CVO, and the relationship between the intact ratio and the stress of necrosis, has never been addressed. The purpose of the study was to evaluate the influence of CVO on the stress reduction in necrotic bone using a finite element analysis (FEA) with different CE angles. Methods CVO finite element models of the hip joint were simulated with a lesion of 60°. The osteotomy angles were divided into four configurations (15°, 20°, 25°, and 30°), and three types (A, B, and C1) of lesions were established based on the Japanese Investigation Committee (JIC) classification. In addition, two CE angles (18° and 33°) of acetabulum were considered. The maximum and mean von Mises stress were analyzed in terms of the necrotic bone by a physiological loading condition. Moreover, the correlation of the intact ratio measured in 3D and the stress distribution after CVO was analyzed. Results Stress reduction was obtained after CVO. For type B, the CVO angle was 20° (0.61 MPa), and for type C1, the CVO angle was 30° (0.77 MPa), if the mean stress level was close to type A (0.61 MPa), as a standard. The maximum and mean von Mises stress were higher in the CE angle of 18°models, respectively. The intact ratio measured in 3D had a good negative correlation with stress after CVO and had more influence on stress distribution in comparison to other geometric parameters. Conclusions For making decisions about the biomechanics of CVO, a CVO angle of > 20° was recommended for type B and > 30° was safe for type C1. The risk of progressive collapse was increased in the insufficient situation of the weight-bearing portion after CVO. The intact ratio could provide information about clinical outcomes and stress distribution after CVO.

Sign in / Sign up

Export Citation Format

Share Document