scholarly journals Influence of Occlusal Contact Area on Cusp Deflection and Stress Distribution

2014 ◽  
Vol 15 (6) ◽  
pp. 699-704 ◽  
Author(s):  
Anna Karina Figueiredo Costa ◽  
Thaty Aparecida Xavier ◽  
Tarcisio José Arruda Paes-Junior ◽  
Oswaldo Daniel Andreatta-Filho ◽  
Alexandre Luiz Souto Borges
Keyword(s):  
Stress Distribution ◽  
Contact Area ◽  
Three Dimensional ◽  
Great Influence ◽  
Maximum Principal Stress ◽  
Occlusal Surface ◽  
Load Application ◽  
Element Analysis ◽  
Occlusal Contact ◽  
Contact Areas

ABSTRACT Objective The purpose of this study was to evaluate the effect of occlusal contact area for loading on the cuspal deflection and stress distribution in a first premolar restored with a high elastic modulus restorative material. Materials and methods The Rhinoceros 4.0 software was used for modeling the three-dimensional geometries of dental and periodontal structures and the inlay restoration. Thus, two different models, intact and restored teeth with three occlusal contact areas, 0.1, 0.5 and 0.75 mm2, on enamel at the occlusal surface of buccal and lingual cusps. Finite element analysis (FEA) was performed with the program ANSYS (Workbench 13.0), which generated a mesh with tetrahedral elements with greater refinement in the regions of interest, and was constrained at the bases of cortical and trabecular bone in all axis and loaded with 100 N normal to each contact area. Results To analysis of maximum principal stress, the smaller occlusal contact area showed greater compressive stress in region of load application for both the intact and inlay restored tooth. However, tensile stresses at the occlusal isthmus were similar for all three tested occlusal contact areas (60 MPa). To displacement of the cusps was higher for teeth with inlay (0.46- 0.48 mm). For intact teeth, the smaller contact area showed greater displacement (0.10 mm). For teeth with inlays, the displacement of the cusps were similar in all types of occlusal area. Conclusion Cuspal displacement was higher in the restored tooth when compared to the intact tooth, but there were no significant variations even with changes in the occlusal contact area. Relevance clinical Occlusal contacts have a great influence on the positioning of teeth being able to maintain the position and stability of the mandible. Axial loads would be able to generate more uniform stress at the root presenting a greater concentration of load application in the point and the occlusal surface. Thus, is necessary to analyze the relationship between these occlusal contacts as dental wear and subsequent occlusal interferences. How to cite this article Costa AKF, Xavier TA, Paes-Junior TJA, Andreatta-Filho OD, Borges ALS. Influence of Occlusal Contact Area on Cusp Deflection and Stress Distribution. J Contemp Dent Pract 2014;15(6):699-704.

Effects of the Mechanical Properties of Veneering Porcelain on Stress Distribution of Dental Zirconia Layered Structure: A Finite Element Model Study

2012 ◽  
Vol 512-515 ◽  
pp. 1797-1801
Author(s):  
Yuan Fu Yi ◽  
Long Quan Shao ◽  
Chen Wang ◽  
Ning Wen ◽  
Bin Deng ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Finite Element ◽  
Stress Distribution ◽  
Principal Stress ◽  
Layered Structure ◽  
Geometric Model ◽  
Middle Layer ◽  
Maximum Principal Stress ◽  
Element Analysis ◽  
Occlusal Contact

The purpose of this study was to study effects of the mechanical properties of veneering porcelain on stress distribution of dental zirconia layered structure by three-dimensional finite element analysis. A 3-D geometric model of the first maxillary molar was established, a tooth preparation was simulated by the Imageware software. A crown was designed and divided into three layers: core, middle layer and outer veneer layer. The elasticity modulus of the middle layer was 70GPa for the control model up to 175GPa for the tested models. Loads of 200N were applied over a 1 mm diameter area beneath the tip of the mesial-distal cusp, simulating typical occlusal contact areas, the stress distribution of the crown systems were analyzed. Results show that within the geometry of the crown configuration, one concentration district of maximum principal stress occurred on the occlusal surface closely proximal to the loading position, several sub-maximum principal stress area were observed, such as margin regions of the mesial face, lingual face, distal faces, buccal face and occlusal fossa. Middle layer with higher modulus can effectively disperse the stress concentration in the layered zirconia all-ceramic crown system.

scholarly journals Comparative Stress Evaluation between Bilayer, Monolithic and Cutback All-Ceramic Crown Designs: 3D Finite Element Study

Prosthesis ◽  
2021 ◽  
Vol 3 (2) ◽  
pp. 173-180
Author(s):  
Nathália de Carvalho Ramos ◽  
Gabriela Freitas Ramos ◽  
Marcela Moreira Penteado ◽  
Renata Marques de Melo ◽  
Alexandre Luiz Souto Borges ◽  
...  
Keyword(s):  
Finite Element ◽  
Stress Distribution ◽  
Mechanical Response ◽  
Three Dimensional ◽  
Maximum Principal Stress ◽  
Mechanical Analysis ◽  
Element Analysis ◽  
All Ceramic ◽  
Homogeneous Stress ◽  
Ceramic Crown

Different all-ceramic crown designs are available to perform indirect restoration; however, the mechanical response of each model should still be elucidated. The study aims to evaluate the stress distribution in three different zirconia crown designs using finite element analysis. Different three-dimensional molar crowns were simulated: conventional bilayer zirconia covered with porcelain, a monolithic full-contour zirconia crown, and the cutback modified zirconia crown with porcelain veneered buccal face. The models were imported to the computer-aided engineering (CAE) software. Tetrahedral elements were used to form the mesh and the mechanical properties were assumed as isotropic, linear and homogeneous materials. The contacts were considered ideal. For the static structural mechanical analysis, 100 N occlusal load was applied and the bone tissue was fixed. Maximum principal stress showed that the stress pattern was different for the three crown designs, and the traditional bilayer model showed higher stress magnitude comparing to the other models. However, grayscale stress maps showed homogeneous stress distribution for all models. The all-ceramic crown designs affect the stress distribution, and the cutback porcelain-veneered zirconia crown can be a viable alternative to adequate function and esthetic when the monolithic zirconia crown cannot be indicated.

scholarly journals Evaluation of the stress distribution in the cortical bone caused by variations in implant applications in patients with bruxism: A three-dimensional finite element analysis

2021 ◽  
Vol 11 (Suppl. 1) ◽  
pp. 194-200
Author(s):  
Yakup Kantaci ◽  
Sabiha Zelal Ülkü
Keyword(s):  
Finite Element ◽  
Stress Distribution ◽  
Cortical Bone ◽  
Principal Stress ◽  
Three Dimensional ◽  
Maximum Principal Stress ◽  
Element Analysis ◽  
Minimum Principal Stress ◽  
Dimensional Finite Element ◽  
Three Dimensional Finite Element

Aim: To evaluate the stress distribution in the cortical bone under parafunctional forces with different occlusal thicknesses, monolithic zirconia with different implant diameters, and number variations in implant-supported fixed prosthetic restorations applied in patients with bruxism. Methodology: The tomographic sections of the previously registered mandible were used in order to model the mandible. Modeled bone height is 30 mm, cortical bone thickness is 1.5 mm, and trabecular bone thickness is modeled as 13 mm. By placing two implants in the created bone model, a three-member main model (Group 1), the number of implants was increased, three implants supported the Group 2 models, the diameter of the implants was increased, and the Group 3 models were created. The created Group 1, 2, 3 models, the occlusal thickness was divided into subgroups with 1.0, 1.5, and 2.0 mm, respectively (Groups A, B, and C). The groups were applied in two directions: vertical and 30o oblique. Stress values under forces were analyzed by finite element stress analysis. Results: Under vertical loading, the maximum principal stress value in the cortical bone was found to be lowest in Group 2C, and the highest maximum principal stress value was found in Group 1A. The minimum principal stress value in the cortical bone was found to be the lowest in Group 3C, and the highest minimum principal stress value was found in Group 1A. Under oblique loading, the maximum principal stress value in the cortical bone was found to be the lowest in Group 3C and the highest maximum principal stress value was found in Group 1A. The minimum principal stress value in the cortical bone was found to be lowest in Group 3C, and the highest minimum principal stress value was found in Group1A. Conclusion: Stresses caused by oblique forces are more than vertical forces. Increasing the occlusal thickness of the implant fixed prosthesis material, implant diameter, and number reduce the minimum and maximum principal stress values in the cortical   How to cite this article: Kantaci Y, Ülkü SZ. Evaluation of the stress distribution in the cortical bone caused by variations in implant applications in patients with bruxism: A three-dimensional finite element analysis. Int Dent Res 2021;11(Suppl.1):194-200. https://doi.org/10.5577/intdentres.2021.vol11.suppl1.27   Linguistic Revision: The English in this manuscript has been checked by at least two professional editors, both native speakers of English.

scholarly journals Effect of three different veneering techniques on the stress distribution and in vitro fatigue behavior of core-veneer all-ceramic fixed partial dentures

2021 ◽  
Vol 15 (3) ◽  
pp. 188-196
Author(s):  
Alexandre Luiz Souto Borges ◽  
Anna Karina Figueiredo Costa ◽  
Amanda Maria de Oliveira Dal Piva ◽  
Alana Barbosa Alves Pinto ◽  
João Paulo Mendes Tribst
Keyword(s):  
Stress Distribution ◽  
Fatigue Behavior ◽  
Three Dimensional ◽  
Maximum Principal Stress ◽  
Elastic Behavior ◽  
Three Dimensional Model ◽  
Element Analysis ◽  
Second Molar ◽  
Linear Elastic

Background. The present study aimed to evaluate the influence of the veneering technique on the tensile stress distribution and survival of full-ceramic fixed dental prostheses (FDPs). Methods. A three-dimensional model of an FDP was modeled on a second premolar and a second molar with a pontic between them for finite element analysis (FEA). The groups were divided according to the veneering technique: conventional stratification, rapid layer, and CAD-on techniques. A mesh control test determined the number of elements and nodes. The materials’ properties were attributed to each solid component with isotropic, homogeneous, and linear elastic behavior. For the in vitro fatigue test (n=30), the FDPs were cemented on dentin analog abutments and submitted to 2×106 mechanical cycles (100 N at 3 Hz). Results. Maximum principal stress showed that the connector between the pontic and the second molar concentrated higher stresses, regardless of the techniques: Rapid layer (6 MPa)> CAD-on (5.5 MPa)> conventional stratification (4 MPa). The conventional stratification technique concentrated high stresses at the interface between the framework and veneering ceramic (2 MPa), followed by the rapid layer (1.8 MPa) and CAD-on (1.5 MPa) techniques. The crowns fabricated using the rapid layer and CAD-on techniques exhibited a 100% survival rate, while the conventional stratification group had 0% survival. Conclusion. Even with similar stress distribution between the veneering techniques, the conventional stratification technique was more prone to failure under fatigue due to higher defects incorporated than CAD-on and rapid layer techniques.

Influence of Different Soft Liners on Stress Distribution in Peri-Implant Bone Tissue During Healing Period. A 3D Finite Element Analysis

2013 ◽  
Vol 39 (5) ◽  
pp. 575-581 ◽  
Author(s):  
Mateus Bertolini Fernandes dos Santos ◽  
Rafael Leonardo Xediek Consani ◽  
Marcelo Ferraz Mesquita
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Stress Distribution ◽  
Three Dimensional ◽  
Maximum Principal Stress ◽  
Simulation Software ◽  
Control Group ◽  
Complete Dentures ◽  
Element Analysis ◽  
Three Dimensional Models

The aim of this study was to evaluate the stress distribution in the bone adjacent to submerged implants during masticatory function in conventional complete dentures with different soft liners through finite element analysis. Three-dimensional models of a severely resorbed mandible with 2 and 4 submerged implants in the anterior region were created and divided into the following situations: (1) conventional complete dentures (control group); and conventional complete dentures with different soft liner materials, (2) Coe-Comfort, (3) Softliner, and (4) Molteno Hard. The models were exported to mechanical simulation software and 2 simulations were done with the load in the inferior right canine (35 N) and the inferior right first molar (50 N). The data were qualitatively evaluated using the maximum principal stress and microstrain values given by the software. The use of soft liners provides decreased levels of stress and microstrains in peri-implant bone when the load was applied to canine teeth. Considering all of the values obtained in this study, the use of softer materials is the most suitable for use during the period of osseointegration.

Effects of occlusal scheme on All-on-Four abutments, screws and prostheses: A three-dimensional finite element study

2020 ◽  
Author(s):  
Nurullah Türker ◽  
Hümeyra Tercanlı Alkış ◽  
Steven J Sadowsky ◽  
Ulviye Şebnem Büyükkaplan
Keyword(s):  
Finite Element ◽  
Three Dimensional ◽  
Good Prognosis ◽  
Von Mises Stress ◽  
Element Analysis ◽  
Group Function ◽  
Occlusal Contact ◽  
Maximum Deformation ◽  
Contact Points ◽  
Von Mises

An ideal occlusal scheme plays an important role in a good prognosis of All-on-Four applications, as it does for other implant therapies, due to the potential impact of occlusal loads on implant prosthetic components. The aim of the present three-dimensional (3D) finite element analysis (FEA) study was to investigate the stresses on abutments, screws and prostheses that are generated by occlusal loads via different occlusal schemes in the All-on-Four concept. Three-dimensional models of the maxilla, mandible, implants, implant substructures and prostheses were designed according to the All-on-Four concept. Forces were applied from the occlusal contact points formed in maximum intercuspation and eccentric movements in canine guidance occlusion (CGO), group function occlusion (GFO) and lingualized occlusion (LO). The von Mises stress values for abutment and screws and deformation values for prostheses were obtained and results were evaluated comparatively. It was observed that the stresses on screws and abutments were more evenly distributed in GFO. Maximum deformation values for prosthesis were observed in the CFO model for lateral movement both in the maxilla and mandible. Within the limits of the present study, GFO may be suggested to reduce stresses on screws, abutments and prostheses in the All-on-Four concept.

scholarly journals Three-Dimensional Finite Element Analysis of Stress Distribution in a Tooth Restored with Full Coverage Machined Polymer Crown

2021 ◽  
Vol 11 (3) ◽  
pp. 1220
Author(s):  
Azeem Ul Yaqin Syed ◽  
Dinesh Rokaya ◽  
Shirin Shahrbaf ◽  
Nicolas Martin
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Stress Distribution ◽  
Three Dimensional ◽  
Intraoral Scanner ◽  
Element Analysis ◽  
Dental Ceramic ◽  
Dimensional Finite Element ◽  
Three Dimensional Finite Element ◽  
Ceramic Crown

The effect of a restored machined hybrid dental ceramic crown–tooth complex is not well understood. This study was conducted to determine the effect of the stress state of the machined hybrid dental ceramic crown using three-dimensional finite element analysis. Human premolars were prepared to receive full coverage crowns and restored with machined hybrid dental ceramic crowns using the resin cement. Then, the teeth were digitized using micro-computed tomography and the teeth were scanned with an optical intraoral scanner using an intraoral scanner. Three-dimensional digital models were generated using an interactive image processing software for the restored tooth complex. The generated models were imported into a finite element analysis software with all degrees of freedom concentrated on the outer surface of the root of the crown–tooth complex. To simulate average occlusal load subjected on a premolar a total load of 300 N was applied, 150 N at a buccal incline of the palatal cusp, and palatal incline of the buccal cusp. The von Mises stresses were calculated for the crown–tooth complex under simulated load application was determined. Three-dimensional finite element analysis showed that the stress distribution was more in the dentine and least in the cement. For the cement layer, the stresses were more concentrated on the buccal cusp tip. In dentine, stress was more on the cusp tips and coronal 1/3 of the root surface. The conventional crown preparation is a suitable option for machined polymer crowns with less stress distribution within the crown–tooth complex and can be a good aesthetic replacement in the posterior region. Enamic crowns are a good viable option in the posterior region.

scholarly journals Folding photopolymerized origami sheets by post-curing

2021 ◽  
Vol 3 (1) ◽  
Author(s):  
Xiaodong He ◽  
Christopher-Denny Matte ◽  
Tsz-Ho Kwok
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Stress Distribution ◽  
Maximum Principal Stress ◽  
Second Step ◽  
Post Processing ◽  
Element Analysis ◽  
Digital Light Processing ◽  
Processing Step ◽  
Lower Maximum

AbstractThe paper presents a novel manufacturing approach to fabricate origami based on 3D printing utilizing digital light processing. Specifically, we propose to leave part of the model uncured during the printing step, and then cure it in the post-processing step to set the shape in a folded configuration. While the cured regions in the first step try to regain their unfolded shape, the regions cured in the second step attempt to keep their folded shape. As a result, the final shape is obtained when both regions’ stresses reach equilibrium. Finite element analysis is performed in ANSYS to obtain the stress distribution on common hinge designs, demonstrating that the square-hinge has a lower maximum principal stress than elliptical and triangle hinges. Based on the square-hinge and rectangular cavity, two variables—the hinge width and the cavity height—are selected as principal variables to construct an empirical model with the final folding angle. In the end, experimental verification shows that the developed method is valid and reliable to realize the proposed deformation and 3D development of 2D hinges.

Finite Element Analysis of Poor Distal Contact of the Femoral Component of a Cementless Hip Endoprosthesis

1993 ◽  
Vol 207 (4) ◽  
pp. 255-261 ◽  
Author(s):  
M Taylor ◽  
E W Abel
Keyword(s):  
Finite Element ◽  
Stress Distribution ◽  
Influencing Factor ◽  
Three Dimensional ◽  
Stress Distributions ◽  
Element Analysis ◽  
Hip Endoprosthesis ◽  
Applied Loading ◽  
Femoral Geometry ◽  
Contact Models

The difficulty of achieving good distal contact between a cementless hip endoprosthesis and the femur is well established. This finite element study investigates the effect on the stress distribution within the femur due to varying lengths of distal gap. Three-dimensional anatomical models of two different sized femurs were generated, based upon computer tomograph scans of two cadaveric specimens. A further six models were derived from each original model, with distal gaps varying from 10 to 60 mm in length. The resulting stress distributions within these were compared to the uniform contact models. The extent to which femoral geometry was an influencing factor on the stress distribution within the bone was also studied. Lack of distal contact with the prosthesis was found not to affect the proximal stress distribution within the femur, for distal gap lengths of up to 60 mm. In the region of no distal contact, the stress within the femur was at normal physiological levels associated with the applied loading and boundary conditions. The femoral geometry was found to have little influence on the stress distribution within the cortical bone. Although localized variations were noted, both femurs exhibited the same general stress distribution pattern.

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