scholarly journals Stress Distribution, Tooth Remaining Strain, and Fracture Resistance of Endodontically Treated Molars Restored Without or With One or Two Fiberglass Posts And Direct Composite Resin

2017 ◽  
Vol 42 (6) ◽  
pp. 646-657 ◽  
Author(s):  
LM Barcelos ◽  
AA Bicalho ◽  
C Veríssimo ◽  
MP Rodrigues ◽  
CJ Soares
Keyword(s):  
Stress Distribution ◽  
Root Canal ◽  
Fracture Resistance ◽  
Composite Resin ◽  
Three Dimensional ◽  
Fracture Load ◽  
The Other ◽  
Element Analysis ◽  
Tooth Structure ◽  
Fracture Modes

ABSTRACT Objectives: To evaluate the effects of direct composite resin without a post or with one or two fiberglass posts on the restoration of severely compromised endodontically treated molars. Methods and Materials: Forty-five molars with 2 mm of “remaining tooth structure” were divided into three groups: Wfgp, restored with Filtek Z350XT without a fiberglass post; 1fgp, restored with Z350XT with one fiberglass post in the distal root canal; and 2fgp, restored with Z350XT with two fiberglass posts, one in the distal root canal and the other in the mesial-buccal root canal. The teeth were load cycled. Tooth remaining strain was measured using strain gauges (n=10) at two moments: TrSt-100 N, during 100 N occlusal loading, and TrSt-Fr, at fracture load. Fracture resistance was calculated, and fracture mode was classified. The elastic modulus and Vickers hardness were calculated using dynamic indentation (n=5). Stress distribution was analyzed by three-dimensional finite element analysis. Results: The use of two fiberglass posts resulted in lower fracture resistance than was noted in the groups with one fiberglass post and without fiberglass posts. The lingual surface of the remaining tooth had higher strain values than the buccal surface, regardless of the restorative technique and moment of evaluation. The absence of a fiberglass post resulted in significantly higher strain values and more irreparable fracture modes than were noted in the other groups. The use of one fiberglass post had a better strain/fracture resistance ratio. Stresses were concentrated in the occlusal portion of the post and in the furcation region. The presence of one fiberglass post resulted in better stress distribution in the entire distal root dentin, reducing stress on the critical areas. Conclusions: The use of one fiberglass post for restoring molars with direct composite resin resulted in higher fracture resistance than did the use of two fiberglass posts; it also resulted in better tooth remaining strain and stress distribution and more reparable fracture modes than were seen in the group without a fiberglass post.

scholarly journals Effect of Base and Inlay Restorative Material on the Stress Distribution and Fracture Resistance of Weakened Premolars

2015 ◽  
Vol 40 (4) ◽  
pp. E158-E166 ◽  
Author(s):  
ACO Souza ◽  
TA Xavier ◽  
JA Platt ◽  
ALS Borges
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Stress Concentration ◽  
Stress Distribution ◽  
Fracture Resistance ◽  
Composite Resin ◽  
Testing Machine ◽  
Control Group ◽  
Element Analysis ◽  
Tooth Structure

SUMMARY The purpose of this study was to evaluate the influence of direct base and indirect inlay materials on stress distribution and fracture resistance of endodontically treated premolars with weakened cusps. Forty healthy human premolars were selected; five were left intact as controls (group C+), and the others were subjected to endodontic treatment and removal of buccal and lingual cusp dentin. Five teeth were left as negative controls (group C−). The remaining 30 teeth were divided into two groups according to the direct base material (glass ionomer [GIC] or composite resin [CR]). After base placement, each group was subjected to extensive inlay preparation, and then three subgroups were created (n=5): no inlay restoration (GIC and CR), restored with an indirect composite resin inlay (GIC+IR and CR+IR), and restored with a ceramic inlay (GIC+C and CR+C). Each specimen was loaded until fracture in a universal testing machine. For finite element analysis, the results showed that the removal of tooth structure significantly affected fracture resistance. The lowest values were presented by the negative control group, followed by the restored and based groups (not statistically different from each other) and all lower than the positive control group. In finite element analysis, the stress concentration was lower in the restored tooth compared to the tooth without restoration, whereas in the restored teeth, the stress concentration was similar, regardless of the material used for the base or restoration. It can be concluded that the inlay materials combined with a base showed similar behavior and were not able to regain the strength of intact tooth structure.

scholarly journals Biomechanical Assessment of the Influence of Inlay/Onlay Design and Material on Stress Distribution in Nonvital Molars

2021 ◽  
Author(s):  
Ayham Darwich ◽  
Abeer Aljareh ◽  
Omar Aladel ◽  
Szabolcs Szávai ◽  
Hasan Nazha
Keyword(s):  
Stress Distribution ◽  
Composite Resin ◽  
Three Dimensional ◽  
Lithium Disilicate ◽  
Element Analysis ◽  
Mandibular Molar ◽  
Composite Resin Restorations ◽  
Von Mises ◽  
Three Dimensional Finite Element ◽  
Almost All

Abstract Objectives The aim of this study was to evaluate the influence of inlays/onlays with or without pulp extension from different materials on stress distribution in endodontically treated molars by three-dimensional finite element analysis (3D FEA). Materials and Methods We used 3D mandibular molar models in this study. The models represented mesio-occluso-distal (MOD) cavities restored by inlays, onlays that covered buccal cusps, and onlays that covered all cusps with pulp extension (modified inlay/onlay) or without pulp extension (conventional inlay/onlay). Three materials (L: lithium disilicate glass-ceramic, P: polymer-infiltrated ceramic network [PICN], and C: nanofilled composite resin) were utilized. A force of 600 N was applied vertically and obliquely. Stress distribution in FEA models was analyzed using the von Mises theory. Results The results revealed that an oblique load generated higher stresses than vertical load. Composite resin restorations transmitted almost all the stress to the neighboring tooth structures, while lithium disilicate ceramic restorations absorbed most of the stresses. Moreover, modified inlays and onlays with pulp extension proved better than conventional inlays/onlays in terms of stress redistribution in dental structures. Onlays showed a better pattern of stress distribution than inlays within the restoration and the restored tooth. Conclusions According to stress distribution in dental structures, modified lithium disilicate ceramic onlays with pulp extension have been found to be the best choice to restore endodontically treated molars among the studied restorations.

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.

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.

scholarly journals Three-Dimensional Finite Element Analysis of the Veneer—Framework Thickness in an All-Ceramic Implant Supported Fixed Partial Denture

Ceramics ◽  
2021 ◽  
Vol 4 (2) ◽  
pp. 199-207
Author(s):  
Lohitha Kalluri ◽  
Bernard Seale ◽  
Megha Satpathy ◽  
Josephine F. Esquivel-Upshaw ◽  
Yuanyuan Duan
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Stress Distribution ◽  
Three Dimensional ◽  
Ct Scanner ◽  
Element Analysis ◽  
Partial Denture ◽  
Fixed Partial Denture ◽  
Occlusal Surfaces ◽  
All Ceramic

This study was performed as an adjunct to an existing clinical study to validate the effect of veneer: framework thickness ratio on stress distribution in an implant-supported all-ceramic fixed partial denture. Two commercially available titanium dental implants with corresponding customized abutments and a patient-retrieved all-ceramic fixed partial denture were scanned using a high-resolution micro-CT scanner. Reconstructed 3D objects, along with a simulated bone surface, were incorporated into a non-manifold assembly and meshed simultaneously using Simpleware software (Synopsys Simpleware ScanIP Version P-2019.09; Mountain View, CA). Three such volume meshes (Model A, Model B, Model C) corresponding to veneer: framework thickness ratios of 3:1, 1:1, and 1:3 respectively were created, and exported to a finite element analysis software (ABAQUS). An axial load of 110 N was applied uniformly on the occlusal surfaces to calculate the static stresses and contour plots were generated in the post-processing module. From the data obtained, we observed optimum stress distribution in Model B. Also, the tensile stresses were concentrated in the posterior connector region of the prosthesis in all three models tested. Within the limitations of this study, we can conclude that equal thickness of veneer and framework layers would aid in better stress distribution.

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.

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