Post-gel and Total Shrinkage Stress of Conventional and Bulk-fill Resin Composites in Endodontically-treated Molars

2020 ◽  
Vol 45 (5) ◽  
pp. E217-E226
Author(s):  
RA da Silva Pereira ◽  
GF de Bragança ◽  
ABF Vilela ◽  
RA de Deus ◽  
RR Miranda ◽  
...  
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Composite Resin ◽  
Composite Resins ◽  
Shrinkage Stress ◽  
Element Analysis ◽  
Posterior Teeth ◽  
Polymerization Shrinkage ◽  
Total Shrinkage ◽  
Selection Of

Clinical Relevance The clinician should consider the polymerization shrinkage stress when selecting a composite resin for posterior restorations. The use of post-gel shrinkage values should guide the selection of a composite resin for posterior teeth. SUMMARY Objectives: The objective of this study was to evaluate the effect of the method used for calculation of polymerization shrinkage, total or post-gel, on the shrinkage stress of conventional and bulk-fill composite resins for restoring endodontically treated teeth using finite element analysis. Methods and Materials: Four composite resins were tested for post-gel shrinkage (P-Shr) by the strain-gauge test and total shrinkage (TShr) using an optical method (n=10). Two conventional composite resins, Filtek Z350 XT (3M-ESPE; Z350) and TPH3 Spectrum (Dents-ply; TPH3) and two bulk-fill composite resins. Filtek Bulk-Fill Posterior (3M-ESPE; POST) SureFil SDR flow (Dentsply; SDR) were tested. Elastic modulus (E), diametral tensile strength (DTS), and compressive strength (CS) were also determined (n=10). The residual shrinkage stress was evaluated by finite element analysis with four restorative techniques: incremental with Z350 and TPH3; SDR/TPH3 (two bulk increments of 4 mm and two occlusal increments); and two bulk increments of 5 mm for POST. Data for P-Shr, T-Shr, E, DTS, and CS were analyzed by analysis of variance and Tukey’s test (α=0.05), and residual shrinkage was analyzed quantitatively and qualitatively by the modified von Mises criteria. Results: SDR had the lowest CS values, POST and TPH3 had similar and intermediate values, and Z350 had the highest CS. TPH3 and Z350 had similar DTS values and values higher than SDR. Z350 and POST had higher P-Shr, and SDR had lower T-Shr. T-Shr resulted in higher shrinkage stress than P-Shr values. SDR/TPH3 resulted in higher shrinkage stress when using T-Shr and lower values when using the P-Shr value. Conclusion: T-Shr resulted in higher stress in the enamel and in root dentin close to the pulp chamber than P-Shr values. The selection of the T-Shr or P-Shr changed the ranking of the shrinkage stress of the tested composite resin.

scholarly journals Influence of Cement Thickness on the Polymerization Shrinkage Stress of Adhesively Cemented Composite Inlays: Photoelastic and Finite Element Analysis

Oral ◽  
2021 ◽  
Vol 1 (2) ◽  
pp. 168-180
Author(s):  
Larissa Mendes Campaner ◽  
Alana Barbosa Alves Pinto ◽  
Amir Mohidin Demachkia ◽  
Tarcísio José de Arruda Paes-Junior ◽  
Clóvis Pagani ◽  
...  
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Film Thickness ◽  
Resin Cement ◽  
Shrinkage Stress ◽  
Element Analysis ◽  
Polymerization Shrinkage ◽  
Photoelastic Analysis ◽  
Group 2 ◽  
Group 1

The objective of this study was to analyze the effect of cement thickness on the strain and stresses resulting from the polymerization of resin cement using photoelasticity and Finite Element Analysis (FEA). For this study, twenty upper first premolars with inlay cavity preparation were constructed from photoelastic resin and restored with composite resin inlay. The samples were divided into two groups (n = 10) according to the film thickness of resin cement material. For Group 1, the film thickness was 100 μm; for Group 2, the film thickness was 400 μm. After polymerization of the cement, photoelastic analysis and finite element analysis (FEA) were performed. In the photoelastic analysis, Group 2 showed higher strain with the presence of second-order fringe even after 24 h. In Group 1, the formation of first order fringes was not observed, even after 24 h. In the FEA analysis, the greatest cusp deflection and tensile stress occurred in Group 2 (0.00026 mm and 0.305 MPa, respectively) due to the polymerization shrinkage in the lingual cusp compared to Group 1 (0.000107 mm and 0.210 MPa, respectively). It can be concluded that the thickness of the resin cement influences the cusp deflection, with the greater thickness of the cement layer, the greater stresses and deformations in the tooth structure occur.

scholarly journals THE COMPARISON OF RESIN-BASED COMPOSITES PHYSICAL PROPERTIES BETWEEN BULK-FILL TECHNIQUE AND INCREMENTAL TECHNIQUE

2021 ◽  
Vol 6 (1) ◽  
pp. 85
Author(s):  
Rahmi Khairani Aulia
Keyword(s):  
Physical Properties ◽  
Composite Resin ◽  
Color Stability ◽  
Composite Resins ◽  
Shrinkage Stress ◽  
Restorative Material ◽  
Polymerization Shrinkage ◽  
Advantages And Disadvantages ◽  
Restoration Technique ◽  
Restoration Failure

ABSTRACT:Composite resins are currently the most popular restorative material in dentistry. This is due to good aesthetics and maximum conservation ability. Behind these advantages, there are disbenefits of composite resin materials, such as polymerization shrinkage, which can lead to restoration failure. Various attempts have been investigated to reduce the shrinkage incidence of composite resins, one of which is the technique of placing the restorative material into the cavity. The restoration filling technique is recognized as a significant factor in shrinkage stress. By using a special filling technique, the polymerization shrinkage damage stress can be reduced. There are several techniques in performing composite resin fillings, including bulk and incremental techniques. These techniques have their respective advantages and disadvantages. The aim of this literature review was to compare the physical properties of composite resin restorations with bulk filling and incremental techniques. Physical properties that being studied include polymerization shrinkage, stress shrinkage, degree of conversion, bonding strength, water resorption, color stability, and temperature increase. Comparing the two techniques, composite resin with incremental filling technique has superior physical properties compared to bulk technique. From the comparison of the two techniques, the composite resin with incremental filling technique has superior physical properties compared to the bulk technique, especially in higher conversion which causes lower shrinkage stress. This situation makes the incremental technique provide better bond strength, water resorption, color stability, and lower temperature rise.Keywords: Bulk, Composite Resin, Incremental,  Physical Properties, Restoration, Restoration Technique

scholarly journals Modified Technique of Porcelain Laminate Veneer in Premolars with Abfraction Lesions: Three-Dimensional Finite Element Analysis (FEA)

2020 ◽  
Vol 22 (2) ◽  
pp. 120-126
Author(s):  
Larissa Marcia Martins Alves ◽  
Lisseth Patricia Claudio Contreras ◽  
João Paulo Mendes Tribst ◽  
Renata Marques de Melo ◽  
Alexandre Luiz Souto Borges
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Composite Resin ◽  
Glass Ionomer Cement ◽  
Three Dimensional ◽  
Glass Ionomer ◽  
Element Analysis ◽  
3D Fea ◽  
Laminate Veneers ◽  
Ionomer Cement

The incidence of non-carious cervical lesions (NCCLs) has increased as populations are aging, and teeth are increasingly retained for life. Several materials are available to treat these lesions. This study aimed to evaluate the stress distribution of maxillary premolars with NCCLs using three-dimensional (3D) finite element analysis (FEA) according to different restorative techniques. A 3D FEA mathematical model simulating a sound premolar was initially modeled and replicated in 6 more models simulating a tooth with abfraction: G.1 tooth with abfraction; G.2 tooth with abfraction + composite resin restoration; G.3 tooth with abfraction + glass-ionomer cement restoration; G.4 tooth with abfraction + resin composite restoration + porcelain laminate veneers; G.5 tooth with abfraction + glass-ionomer cement + porcelain laminate veneers; and G.6 modified porcelain laminate veneers filling the lesion. All materials and structures were considered linear, elastic, homogeneous and isotropic and the results were expressed as maximum principal stress. Lower stress concentration in dentin was calculated when the tooth was restored with composite resin and glass-ionomer cement. Regarding the veneer techniques, no difference was found to dentin stress among the groups, but the modified veneer concentrated less stress in the restoration than other the techniques. The control group had the highest concentration of stress in the lesion. All techniques decreased the stress concentration inside the NCCLs and the indirect veneer filling the lesion presented better biomechanical behavior than the veneer cemented above direct restorations.  Keywords: Finite Element Analysis. Dental Veneers. Ceramics. Bicuspid. Resumo A incidência de lesões cervicais não-cariosas (LCNC) tem aumentado, uma vez que a população tem envelhecido com uma menor perda de elementos dentários. Diferentes materiais estão disponíveis para tratar dessas lesões. Este estudo objetivou avaliar a distribuição de tensão de pré-molares superiores com LCNC por meio da análise tridimensional (3D) de elementos finitos (FEA) de acordo com diferentes técnicas restauradoras. Um modelo matemático 3D FEA simulando um pré-molar íntegro foi modelado e replicado em mais 6 modelos simulando um dente com abfração: G.1 dente com abfração; G.2 dente com abfração + resina composta; G.3 dente com abfração + cimento de ionômero de vidro; G.4 dente com abfração + resina composta + faceta; G.5 dente com abfração + cimento de ionômero de vidro + faceta cerâmica e G.6 com faceta cerâmica modificada, preenchendo a lesão. Todos os materiais e estruturas foram considerados lineares, elásticos, homogêneos e isotrópicos e os resultados foram expressos como máxima tensão principal. Menor concentração de tensão na dentina foi calculada quando o dente foi restaurado com resina composta ou cimento de ionômero de vidro. Dentre os grupos com laminados, não houve diferença para a dentina, entretanto a faceta modificada apresentou menor concentração de tensão na restauração. O grupo controle apresentou a maior concentração de tensão na lesão. Todas as técnicas restauradoras diminuíram a concentração de tensão no interior das LCNCs e dentre as técnicas com laminados a faceta modificada apresentou o melhor comportamento biomecânico. Palavras-chave: Análise de Elementos Finitos. Facetas Dentárias. Cerâmica. Dente Pré-Molar.

scholarly journals Optimisation of Coating Properties for Fibre Optic Smart Structures using Finite Element Analysis

1994 ◽  
Vol 3 (5) ◽  
pp. 096369359400300
Author(s):  
M. Hadjiprocopiou ◽  
G.T. Reed ◽  
L. Hollaway ◽  
A.M. Thorne
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Optical Fibre ◽  
Smart Material ◽  
Material System ◽  
Careful Selection ◽  
Coating Properties ◽  
Stress Concentrations ◽  
Element Analysis ◽  
Selection Of

Finite Element analysis is used to determine and to minimise the stress concentrations which arise in a “Smart” material system due to the embedded optical fibre sensors. The FE results show that with careful selection of the coating stiffness and thickness the stress concentrations caused by the fibre inclusion in the host material can be reduced.

Finite Element Analysis of Thermal Stress for Femoral Prosthesis

2013 ◽  
Vol 750-752 ◽  
pp. 2212-2215
Author(s):  
Mo Nan Wang
Keyword(s):  
Finite Element Method ◽  
Finite Element Analysis ◽  
Finite Element ◽  
Coefficient Of Thermal Expansion ◽  
Physical Property ◽  
Prosthetic Material ◽  
Femoral Prosthesis ◽  
Interface Failure ◽  
Element Analysis ◽  
Selection Of

Based on the thermo elasticity theory, the stress of femur prosthesis system was analyzed using finite element method. An evaluation for the selection of prosthetic material was presented after discussing the thermo physical property of material which had an effect on the stress of femur prosthesis system. The results indicate that the interface failure is the primary failure form of the femoral prosthesis system and the interface failure is accelerated for the reason of the thermal effect. So the prosthesis with low coefficient of thermal expansion should be selected which can moderate the interface failure in the certain degree.

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