Three-dimensional Finite Element Stress Analysis Research Articles

Evaluating Angled Abutments: Three-Dimensional Finite Element Stress Analysis of Anterior Maxillary Implants

Restorative dentistry is the repairing of damaged teeth and restoring oral health and function. Dental implants are typically placed within the cortical bone of the jaw to provide stability and support for prosthetic restorations. The successful restoration of complex anatomical features of the maxillary anterior is difficult for prosthodontists. Using a 3D slicer, CT scan images were used to create a detailed three-dimensional model of the maxilla bone. This study utilizes ANSYS Workbench, a finite element software program, to analyze the abutment angles, ranging from 0° to 25°, and the impact stress distribution within peri-implant bone. The outcomes of our studies align with and substantiate certain evidence in the literature documenting bone resorption, specifically at the level of the implant neck and near the cortical bone. The study aims to provide a comprehensive understanding of angled abutment stress patterns in the bone surrounding dental implants, offering valuable insights for clinical applications in critical areas of the mouth.

Three-dimensional finite element stress analysis of surface-mounted inlays in repairing pulp-penetrating non-carious cervical lesion of maxillary first premolar.

This study aimed to explore the stress distribution of surface-mounted inlays with two ceramic materials and different strategies for fiber post-restoration on pulp-penetrating non-carious cervical lesion in a maxillary first premolar to provide minimally invasive and reasonable restorative methods. The cone beam computed tomography data of the standard right upper first premolar were selected. Healthy control (HC) and defective control (DC) finite element models were established. Then, eight experimental models were established according to two different ceramic materials (IPS e.max CAD [LD] and Lava Ultimate [LU]) and different locations of fiber post (without fiber post [NP], fiber post in buccal root canal [B], fiber post in palatal root canal [P], fiber post in both root canals [BP]), namely, LDNP, LDB, LDP, LDBP, LUNP, LUB, LUP, and LUBP. Axial load F1 and lateral load F2 were applied. Maximum principal stress and displacement of the buccal tip were investigated using finite element analysis software. Then, the percentage change of the following indicators in each experimental group was analyzed: stress of defective tip with group DC, stress of enamel and dentine, and displacement of buccal tips with group HC. It was considered similar when the percentage change was less than 5%. LD and LU groups could effectively reduce the stress of the defective tip, but the decreasing amplitude in the former was greater than that of the latter. For the stress of surface-mounted inlays and resin adhesive layer, LD groups were higher than LU groups, and no significant difference in stress peak was found among different experimental groups in the same material. In addition, fiber posts in double root canals could significantly reduce buccal tip displacement. For pulp-penetrating non-carious cervical lesions, the restorative strategy of surface-mounted inlays could be applied. Compared with Lava Ultimate, IPS e.max CAD could better protect the defective tip tooth. Furthermore, fiber posts in double root canals could decrease overall deformation and increase the retention of surface-mounted inlays.

Three-Dimensional Finite Element Stress Analysis of Different Implant-Supported Bridges in the Maxillary Incisal Regions

Three-Dimensional Finite Element Stress Analysis of Different Implant-Supported Bridges in the Maxillary Incisal Regions

Biomechanical study of different fixation constructs for anterior column and posterior hemi-transverse acetabular fractures: a finite element analysis

BackgroundTo compare the biomechanical properties and stability, using a finite element model, of four fixation constructs used for the treatment of anterior column and posterior hemi-transverse (ACPHT) acetabular fractures under two physiological loading conditions (standing and sitting).MethodsA finite element model simulating ACPHT acetabular fractures was created for four different scenarios: a suprapectineal plate combined with posterior column and infra-acetabular screws (SP-PS-IS); an infrapectineal plate combined with posterior column and infra-acetabular screws (IP-PS-IS); a special infrapectineal quadrilateral surface buttress plate (IQP); and a suprapectineal plate combined with a posterior column plate (SP-PP). Three-dimensional finite element stress analysis was performed on these models with a load of 700 N in standing and sitting positions. Biomechanical stress distributions and fracture displacements were analysed and compared between these fixation techniques.ResultsIn models simulating the standing position, high displacements and stress distributions were observed at the infra-acetabulum regions. The degree of these fracture displacements was low in the IQP (0.078 mm), as compared to either the IP-PS-IS (0.079 mm) or the SP & PP (0.413 mm) fixation constructs. However, the IP-PS-IS fixation construct had the highest effective stiffness. In models simulating the sitting position, high fracture displacements and stress distributions were observed at the regions of the anterior and posterior columns. The degree of these fracture displacements was low in the SP-PS-IS (0.101 mm), as compared to the IP-PS-IS (0.109 mm) and the SP-PP (0.196 mm) fixation constructs.ConclusionIn both standing and sitting positions, the stability and stiffness index were comparable between the IQP, SP-PS-IS, and IP-PS-IS. These 3 fixation constructs had smaller fracture displacements than the SP-PP construct. The stress concentrations at the regions of quadrilateral surface and infra-acetabulum suggest that the buttressing fixation of quadrilateral plate was required for ACPHT fractures.

Teeth Restored with Bulk-Fill Composites and Conventional Resin Composites; Investigation of Stress Distribution and Fracture Lifespan on Enamel, Dentin, and Restorative Materials via Three-Dimensional Finite Element Analysis.

the aim of this study was to examine the stress distribution of enamel, dentin, and restorative materials in sound first molar teeth with restored cavities with conventional resin composites and bulk-fill composites, as well as to determine their fracture lifetimes by using the three-dimensional finite element stress analysis method. an extracted sound number 26 tooth was scanned with a dental tomography device and recorded. Images were obtained as dicom files, and these files were transferred to the Mimics 12.00 program. In this program, different masks were created for each tooth tissue, and the density thresholds were adjusted manually to create a three-dimensional image of the tooth, and these were converted to a STL file. The obtained STL files were transferred to the Geomagic Design X program, and some necessary adjustments, such as smoothing, were made, and STP files were created. Cavity preparation and adhesive material layers were created by transferring STP files to the Solidworks program. Finally, a FE model was created in the ABAQUS program, and stress distributions were analyzed. when the bulk-fill composite and conventional resin composite materials were used in the restoration of the cavity, the structures that were exposed to the most stress as a result of occlusal forces on the tooth were enamel, dentin, restorative material, and adhesive material. When the bulk-fill composite material was used in restoration, while the restorative material had the longest fracture life as a result of stresses, the enamel tissue had the shortest fracture life. When the conventional resin composite material was used as the restorative material, it had the longest fracture life, followed by dentin and enamel. when the bulk-fill composite material was used instead of the conventional resin composite material in the cavity, the stress values on enamel, dentin, and adhesive material increased as a result of occlusal forces, while the amount of stress on the restorative material decreased. In the fracture analysis, when the bulk-fill composite material was used instead of the conventional resin composite material, a decrease in the number of cycles required for the fracture of enamel, dentin, and restorative materials was observed as a result of the forces generated in the oral cavity.

Stress analysis of laminated graphite fiber reinforced polymer Panel Stiffened joint with 450 fiber orientation using ANSYS

Large panels made of composite materials are utilised often in the aerospace sector. In most cases, this type of panel will fracture when subjected to a wide variety of stresses and boundary conditions. The panel receives additional rigidity through the addition of a flange, which is also supported by a web. In this study, a three-dimensional finite element stress analysis is performed on a firm panel that consists of a web, a flange, and a panel with an interface between the flange and the panel. The analysis is performed in preparation for an arrangement of composite panels of this sort. The influence that anisotropy, layer stacking sequence, and ply orientation have on the stress components is taken into consideration. For the purpose of this investigation, a graphite-fiber reinforced polymeric (GFRP) composite is used. Laminate arrangements of [45 0 /–45 0 /45 0 /–45 0 ] 2 and [45 0 /–45 0 2 /45 0 ] 2 angle-plied prepregs have been taken. This work makes use of the coupled stress failure criterion in order to forecast the site where damage initiation would take place. The critical point is observed to be around the layer’s front-left border, with a maximum stress concentration of about 125 MPa. Stress values fall as they move from left to right. Negative stress component values have also been observed in a few cases.

Research on Structural Optimization Design of Plate Gate

The bulkhead gate of simple structure, easy fabrication, easy maintenance, safe and reliable degree is high, widely used in water conservancy and hydropower engineering, have stronger effects of spatial structure, this paper adopts three-dimensional finite element stress analysis, modeling and research of the relationship between the structure parameters and the structure performance, and then through the ANSYS software to optimize design. The analysis results show that the optimized gate has lighter weight and saves more materials under the condition of satisfying the strength and stiffness constraints.

EVALUATION OF BIOMECHANICAL EFFECTS OF PROSTHETIC COMPONENTS WITH DIFFERENT MATERIALS ON THE ABUTMENT SCREW

Objectives: The purpose of this study was to evaluate the effects of different resin-based and ceramic superstructure materials and two different abutment types on the stress distribution of the abutment screw using the three-dimensional finite element stress analysis method. Materials and Methods: A three dimensional implant, abutment (zirconia and titanium), abutment screw, crown (zirconia reinforced lithium silicate, lithium disilicate, polymer-infiltrated resin ceramic, and PEEK), and alveolar bone were designed using Rhinoceros 3D modeling software and VRMesh Studio software and combined to form 8 simulations. On the models prepared, loading was made on the lingual tubercule of the maxillary right first premolar crown at an angle of 30° with 150 N force obliquely in the buccolingual direction. The von Mises values obtained from the abutment screw were compared according to the types of abutment and crown materials. Results: The von Mises stress values in the abutment screw were higher in the models using a titanium abutment abutment (on average 1336.24 MPa), and the lower stress values were obtained in the models using a zirconia abutment (on average 964.26 MPa). When the prosthetic material used was changed, no apparent difference was observed in the stress values on the abutment screw. Conclusions: Considering that the abutment screw is the weakest link of the implant system, zirconia abutments can be used reliably in the maxillary first premolar region where aesthetic expectations are high.

The effect of different positions of unerupted lower third molar teeth on the fragility of mandibular angle: Finite element analysis.

The mandibular bone is the largest and strongest bone in comparison to the other bones in the face skeleton. However, it is the most commonly fractured in facial injuries. The location of the fracture in mandible depends on various factors. The relationship of the impacted lower third molar teeth to mandibular angle fracture has been the subject of many epidemiological studies. It is argued that the risk of fracture in mandibular angle is two to four times more when there are particularly an impacted or partially impacted third molar teeth. However, the effect of the position of the impacted tooth on mandibular angle fracture is not clear yet. This study seeks to reveal the effect of third molar teeth that are impacted in various positions on the angle fragility. This study was performed using three-dimensional finite element stress analysis and static linear analysis methodology. Computed tomography (CT) images obtained previously from a patient were used to construct models of the bone tissue. An ILUMA CBCT device (3M Imtec, OK, USA) was used for tomographic scans. Impacted teeth in various positions were digitally modeled separately. Different direction forces were applied to the mandible, the stress values on the bone surrounding the third molar teeth impacted in different positions were determined. Third molar teeth are impacted in mandibular bone in the following positions: mesioangular, vertical, horizontal, and distoangular positions. The study showed that the force that created the highest stress in the Mandibular angle among the modelled groups is the force by ipsilateral angle. For all kinds of impacted teeth, there was more stress accumulation in the buccal area than in the lingual area when the force is from the symphisis.

Biomechanical evaluation of stress distributions at the implant-abutment complex and peri-implant bone around mandibular dental implants with different neck geometries and inclinations.

This study aimed to investigate the effects of the different dental implant neck designs, diameters, and inclinations, on the stress distributions at the mandibular crestal bone and implant-abutment complex, using three-dimensional (3D) finite element stress analysis (FEA) method. Finite element models of three-unit fixed partial dentures supported with two same length implants (10 mm), placed on the second premolar and second molar regions, were designed. Eight different models were designed according to the implants' neck designs (platform switching/traditional), diameters (4.1 mm/4.8 mm) and the tilting angles of the posterior implants (0°/15°). The anterior implants' widths were 4.1 mm and the neck design of the anterior implants matched the posterior implants. Two types of 100-N loads in vertical and 30° oblique directions were applied separately onto each central fossae and functional cusps of the fixed partial dentures crowns. Algor Fempro Software was used for the simulation and evaluation of the stress levels at the implant-abutment complex and the crestal bone. Stress levels measured at the crestal bone were found to be lower for the platform switching models. However, the platform switching design generated higher stress magnitudes within the implant-abutment complex. Inclined placement of posterior implants increased the amount of stress at the crestal bone around both implants. Biomechanically, selection of the largest diameter possible when using tilted platform switched implants may be recommended at the posterior mandible.

Influence of Occlusal Bite Forces on Teeth with Altered Periodontal Support: A Three-Dimensional Finite Element Stress Analysis.

Background:Masticatory forces generate various degrees of stress and strain in the periodontium of teeth which determine the clinical functions and load-bearing capacity of the teeth. There are few in vitro studies that have analyzed stress generated due to combined forces acting on the teeth. Thus, the objective of the present study was to do a comparative analysis of the influence of various stresses on the periodontal ligament and alveolar bone of maxillary central incisor with normal bone height and reduced bone height under simulated standard masticatory using finite element stress analysis.Methodology:A 3D model of the tooth was obtained with the help of ANSYS software. These models were subjected to various oblique forces, i.e., 100N and 235.9N, applied at 45° angle on the lingual surface of the maxillary central incisor and stress values were recorded in three dimensions. The results from FE analysis were analyzed using 3D Von Mises Criteria.Results:It was observed that in healthy periodontium; it was observed that among the periodontal structure studied, the maximum stress levels were exerted on root followed by cortical bone, cancellous bone, and PDL, irrespective of the force, as compared to the diseased periodontium, in which the bone height was reduced, the maximum stresses were on root followed by cortical bone, PDL, and cancellous bone.Conclusion:The main factor governing the success of any periodontal procedure depends on the height of the remaining bone and the amount of force exerted on to the tooth and the stress generated within the tooth. The finite element method could be of substantial importance in this respect as it can assess the stresses of various occlusal forces on the periodontal ligament, root, cortical bone, and cancellous bone of teeth in a periodontally healthy and diseased state.

Angulated versus parallel headless cannulated screw fixation for type 1 capitellum fracture: A finite element study

Aim: The unique shape and vascularization make capitellar fractures challenging to treat. In such cases, screw inclination is crucial to achieve stable fixation. In the present study, we aimed to evaluate the mechanical outcome of the different fixation angles formed by headless cannulated screws for treatment of type 1 capitellum fracture and compared interfragmentary displacement (IFD) using finite element analysis (FEA). Material and Methods: In our study, three-dimensional finite element stress analysis was applied using the isotropic materials and static linear analysis. Stochastic screw inclination scenarios (Case 1, Case 2, Case 3, and Case 4) were generated, and perpendicular application of loads were simulated with magnitudes between 50 and 300 N on the elbow at angulations from 0o to 145o. The IFD in the four different screw inclination pairs were listed in the ANSYS general end processor. Relative IFD was calculated by measuring the total displacements in the X/Y/Z planes from 16 different points.Results: According to the modeling, the magnitude of IFD was significantly different in terms of the force and the case factors under four altered forces. Analysis of displacement exhibited a significant difference in the force values of ‘100N/200N/300N’ and in the screw inclinations of Case 2 only. Although the interaction effect between the Force*Case was observed to be low, the most noticeable results were obtained from the “300N*Case 2.” pair compared to the others (p0.05).Conclusion: Screws used for fracture fixation must maintain an anatomical correction, until it heals. Following a complex trauma such as a capitellar fracture, the elbow joint needs a stable fixation and early mobilization. Our FEA results suggest that the fixation via angled screws can achieve a more stable configuration than the paralleled ones.

Stress Distribution in Four Restorative Methods in Endodontically Treated Maxillary Premolar: A 3D Finite Element Analysis

Introduction: the Restoration of endodontically treated teeth is critical, and the Awareness of stresses developed by oblique and vertical forces in restorative methods take a great role in treatment plans. Due to the anatomical shape and inherent form of the stress distribution premolars, could be lost by fractures. Some fractures such as vertical fracture which is probable in endodontically treated teeth, makes the teeth a candidate for extraction and other surgical procedures. According to this fact that the dental restorations should be conservative, the aim of this study was to determine stress distribution using four composite restorative methods. Methods: Endodontically treated maxillary second premolars were restored with composite resin using four methods. For restoration, the models representing standard Mesio-occlusal-distal (MOD) restoration, cusps capping with thickness of 1 and 2mm, and the use of woven fiber in occlusal part, were prepared. The effects of the different restorative approaches on stress distribution were analyzed using three-dimensional finite element stress analysis. Results: the highest stress rate was observed in MOD tooth restoration and the amount of stress in natural parts of the tooth in woven fiber was found the lowest. Conclusion: The simulation results show that in all models, oblique forces caused more stress than vertical forces. Moreover, there was a slight difference between different types of restorations regarding the magnitude of stress; however, the results obtained from this study showed that woven fiber could partly reduce stresses.

Numerical simulation and operation characteristics analysis of folded line concrete face rockfill dam: case study of Yimeng Pumped storage power station

Take Yimeng pumped storage project as a case of a folded-line concrete face rockfill dam, three-dimensional static finite element stress and deformation analysis is carried out to simulate the characteristics of the dam during construction and storage period, the deformation mechanism of the folded-line concrete face rockfill dam is analysed, and the stress and deformation law of the folded-line concrete face dam is obtained. The analysis shows that the large turning angle of panel is the most obvious factor to increase tensile trend and degree of face slabs and peripheral joints, the connecting plate has contribution to the improve stress and deformation behavior of slabs and peripheral joints. It is suggested to strengthen the research on the tensile properties of the slabs, the connection plate and the waterproof structure.

A three-dimensional finite element stress analysis of two different implant distributions supporting and retaining mandibular overdentures

Statement of Problem: Hinging mandibular overdentures retained by anterior interforaminal implants results in denture rotation and posterior basal bone resorption. Wide spread implant distribution and posterior implant placement can improve overdenture support. Aim of study: To evaluate the biomechanical aspects of novel implant distribution used to support mandibular overdentures and compare it with commonly used design. The novel design consists of mid-symphyseal and bilateral posterior implants in the first molar region as opposed to conventional design with anterior mid-symphyseal and bilateral implants in the canine region.Materials and Methods: Two finite element models were created. In the two models a mid-symphyseal implant was simulated. In the first model (D1), 2 more implants were placed in the canine region bilaterally while for the second model (D2), the 2 additional implants were placed posteriorly in the first molar region. Unilateral vertical and oblique loads were applied on central fossa of right first molar and palatal aspect of central incisors in each model. Von Mises stress distribution was evaluated in the implants and peri-implant bone. Denture displacement was also calculated for each model. Results: There was a slight increase in maximum Von-Mises stress values recorded in both implants and peri-implant bone under both vertical and oblique load in D2 when compared to D1. D1 showed higher denture displacement values when compared to D2. Conclusions: Posterior implant placement resulted in improved denture support and minimal denture displacement on the expense of transferring extra load to the posterior implants. However, increased functional load on posterior implants is expected to have a positive effect on preservation of the residual alveolar ridge. D2 is an acceptable alternative prosthodontic design to D1 when anatomical factor permits.

A comparative biomechanical analysis of suprapectineal and infrapectineal fixation on acetabular anterior column fracture by finite element modeling

Background/aim The aim of this study is to compare the stability and implant stresses of suprapectineal plate with infrapectineal plate in three subconfigurations of the screw types. Materials and methods The stabilities of different fixation methods were compared by finite element analysis on six models. Three infrapectineal and three suprapectineal models each with locked, unlocked, or combined screws were employed. Three-dimensional finite element stress analysis was performed by using isotropic materials with a load of 2.3 kN applied at standing positions. Motion at the fracture line was measured on four different points located on the pubic and iliac sides of the fracture line.Results Infrapectineal plate fixation with unlocked screws was found to be the most stable fixation method with 0.006 mm displacement of fragments in all axes at standing positions. The suprapectineal unlocked method was found to be the most unstable in standing positions with maximum displacement values of 0.46 mm vertical shear movement in the x-axis, –0.14 mm displacement in the y-axis, and –0.33 mm lateral shear in the z-axis. Conclusion The infrapectineal unlocked plate supplies the most stable fixation with the least implant stress, contrary to the suprapectineal unlocked plate, which has the lowest stability and highest implant stresses.

Three-dimensional finite element stress analysis of teeth adjacent to a traumatized incisor.

Dental trauma is the cause of several consequences to the injured tooth. However, the stresses and strains at adjacent teeth non-directly impacted as a possible cause of sequelae are still unknown. The aim of this study was to evaluate the stress distribution in incisors adjacent to an upper central incisor when it suffers a frontal impact in order to identify a potential explanation for sequelae in non-traumatized teeth. A three-dimensional (3D) finite element model of the maxillary central incisors, lateral incisors and canines was created from a cone-beam scan of a patient with normal occlusion. Non-linear dynamic impact analysis was performed, simulating the right central incisor being impacted by a steel ball with a velocity of 10m/s. A functional chewing load (100 N) on the palatal surface of the central incisor was simulated for comparison. Displacements, strains and modified von Mises stresses were calculated for the adjacent teeth. During impact on the central incisor, the adjacent teeth showed root displacement. Considerable stress concentrations were observed on the palatal surfaces, proximal and labial surfaces of teeth adjacent to the traumatized incisor. Stresses in the adjacent teeth were higher than stresses calculated during functional biting. Compressive stresses were concentrated at the proximal areas of the adjacent incisors. High levels of deformation were found in the root dentin of adjacent teeth during the traumatic event. A frontal impact on an anterior tooth generated stresses at the roots of adjacent teeth. These stresses may play a role in clinically observed sequelae of teeth adjacent to traumatized teeth.

A new method for the treatment of unilateral posterior cross-bite: a three-dimensional finite element stress analysis study

BackgroundStress relieving corticoto mies during the treatment of maxillary expansion are needed in adult patients.MethodsThree-dimensional (3D) finite element model was prepared, and finite element analysis was processed to evaluate the stress distributions within the skull and maxillary teeth during surgically assisted rapid maxillary expansion (SARME) treatment.ResultsExpansion forces generated more stress on the corticotomy-applied part of the maxilla. The stress levels decreased dramatically above the corticotomy line.ConclusionAsymmetric transveral maxillary expansion might be achieved from a symmetric force generating screw during SARME treatment. SARME osteotomies may concentrate the stress in the expanding maxilla and reduce the pain in other parts of the cranium.

Finite element analysis of the stability of AO/OTA 43-C1 type distal tibial fractures treated with distal tibia medial anatomic plate versus anterolateral anatomic plate

BackgroundThe treatment of a pilon fracture type is possible from a medial, an anterolateral approach or both medial and lateral. The aim of study was compare the stability of two different plate fixation of a tibia pilon AO-43C1 type fractures. Material and methodsIn this study, three-dimensional finite element stress analysis was applied using isotropic materials and static linear analysis. Loading of 400 N force was applied to the model of a patient fixed in a standing position. In the model, first the fibula was treated by plating and then in one group the pilon fracture was treated by medial plating, and in the other by anterolateral plating. The displacement and stress values of the fragments of the fracture line were compared of the same points in each model. ResultsThe magnitude of the displacement of fragments in the total displacement magnitudes of X, Y, Z axis were measured in the medial plate and anterolateral plate. The anterolateral plate results were similar to those of the medial plate and the displacement values in the Y axis were determined to be lower than in the medial plate. ConclusionIn AO 43 C1 distal tibia fractures, medial or anterolateral plates can be used, and the results of this study showed similar biomechanical stiffness in the two plates.

Assessment of stress changes in dentoalveolar and skeletal structures of the mandible with the miniplate anchored Forsus: A three-dimensional finite element stress analysis study

ObjectiveThe study conducted to assess the effects of a fixed functional appliance (Forsus Fatigue Resistant Device; 3M Unitek, Monrovia, CA, USA) on the mandible with three-dimensional (3D) finite element stress analysis.Materials and MethodsA 3D finite element model of mandible with miniplate at mandibular symphysis was prepared using SolidEdge software along with the plate geometry. The changes were deliberated with the finite element method, in the form of highest von Mises stress and maximum principal stress regions.ResultsMore areas of stress were seen in the model of the mandible at cortical bone in canine region at bone and miniplate interface.ConclusionsThis fixed functional appliance studied by finite element model analysis caused more von Mises stress and principal stress in both the cortical bone and the condylar region.