Evaluation of Mechanical Properties of Composite Materials Used in Dentistry Varying the Inorganic Composition

2015 ◽  
Vol 820 ◽  
pp. 320-324
Author(s):  
T.C.F. Melo-Silva ◽  
C.L. Melo-Silva ◽  
C.F. Carvalho ◽  
A.B. Teixeira ◽  
J.F.C. Lins ◽  
...  
Keyword(s):  
Elastic Modulus ◽  
Thermal Activation ◽  
Elasticity Modulus ◽  
Excitation Pulse ◽  
Composite Resins ◽  
Acoustic Excitation ◽  
Ceramic Filler ◽  
Inorganic Particles ◽  
Inorganic Composition ◽  
Materials Used

The aim of this study was to determine the hardness and the elasticity modulus of the two composite resins base of BISGMA with different inorganic particles: a nanoparticulated with a ceramic withload, (Filtek Z350XT-3M) with and without thermal activation and a microhybrid with no ceramic load (Opallis-FGM). The samples were prepared and subjected to the tests of Vickers hardness (Shimadzu HMV) and acoustic excitation pulse (Sonelastic ®). The samples were divided into three groups: G1-Filtek Z350 XT; G2-Filtek Z350XT MO (subject to further polymerization microwave) and G3-Opallis. The results showed that the hardness of G2 was significantly higher than the groups G1 and G3. The elastic modulus was higher than the G2 to G1 and G3. One can conclude that the resins filled with inorganic ceramic filler showed higher hardness and elastic modulus. The thermal activation increased the hardness and the elasticity modulus of the resin with ceramic load.

Calculations used for assessment of rapid maxillary expansion

ORL ro ◽  
2016 ◽  
Vol 1 (1) ◽  
pp. 24-26
Author(s):  
Ruxandra Bartok ◽  
Bogdan Dimitriu Dimitriu ◽  
Constantin Vârlan ◽  
Radu Stanciu ◽  
Georgiana Moldoveanu ◽  
...  
Keyword(s):  
Tensile Strength ◽  
Elasticity Modulus ◽  
Rapid Maxillary Expansion ◽  
Laboratory Animals ◽  
Maxillary Expansion ◽  
Literature Reference ◽  
Bone Changes ◽  
Upper Jaw ◽  
Materials Used

Rapid maxillary expansion is defined as the release of medio-palatine suture using an orthopedic forces. The role of this procedure is to expand  the upper jaw in order to achieve the  broadening of the upper arch. This study was initiated to quantify the effects of disjunction and post- treatment bone changes, after an adequate contention which lasted for three weeks. This study  is  carried on laboratory animals (common breed rabbit) to determine tensile strength and the elasticity modulus of  biological materials  used in orthdodontics. The results of the study are consistent with those reported in the literature reference.  

scholarly journals Evaluation of Sealing Materials Adhesion to Enamel An in vitro study

2017 ◽  
Vol 54 (1) ◽  
pp. 129-132
Author(s):  
Andreea Simona Pop ◽  
Radu Septimiu Campian ◽  
Mariana Pacurar ◽  
Elina Teodorescu ◽  
Olimpia Bunta ◽  
...  
Keyword(s):  
In Vitro Study ◽  
Specific Method ◽  
High Concentration ◽  
Posterior Teeth ◽  
Inorganic Particles ◽  
Material Homogeneity ◽  
Materials Used ◽  
High Degree ◽  
Pits And Fissures

Sealing the pits and fissures of posterior teeth represents a local and specific method of caries prevention. The aim of this study was to evaluate the adhesion of two materials used in sealing pits and fissures: Pitt and Fisure and Fissurit FX (Voco), with the help of the scanning electronic microscope (SEM). The results of the study revealed a much higher quality of the Fissurit FX (Voco) product both in terms of adhesion to the enamel and material homogeneity. The Pitt and Fisure product showed a high degree of detachment from the enamel, marginal infiltration, large particles and a high concentration of inorganic particles.

Effect of Carbon Black Reinforcing Fillers on Mechanical Properties of NBR Materials Used for the Progressing Cavity Pump

2015 ◽  
Vol 750 ◽  
pp. 339-344 ◽  
Author(s):  
Long Pan ◽  
Jin Zhu Tan ◽  
Liu Fei Fan ◽  
Xue Mei Han
Keyword(s):  
Mechanical Properties ◽  
Mechanical Property ◽  
Tensile Strength ◽  
Elastic Modulus ◽  
Carbon Black ◽  
Heat Resistance ◽  
Tear Strength ◽  
Resistance Property ◽  
Reinforcing Fillers ◽  
Materials Used

Three kinds of reinforcing fillers (i.e. carbon black N330, carbon black N880 and carbon-white) were used to study effect of the reinforcing fillers on the mechanical properties of NBR materials. The NBR materials with various reinforcing fillers were fabricated, and the mechanical property tests were performed in this work. The results show that the carbon black N330 made the NBR material have better tensile strength, hardness, elongation and compression elastic modulus compared to the carbon black N880 and the carbon-white, while the carbon-white made NBR material have better heat resistance, tear strength and elongation compared to the carbon black N330 and the carbon black N880. In addition, the tensile strength, tear strength, elongation and the heat resistance property of the NBR materials increased significantly with the increase of the carbon-white, but the compression elastic modulus decreased with the increase of the carbon-white.

scholarly journals Repair Adhesive Strength of Conventional and Bulk Fill Resins Using Different Bonding Techniques

2021 ◽  
Vol 22 (3) ◽  
pp. 185-190
Author(s):  
Wilian Segatto Zanelli ◽  
Mariana Dias Flor-Ribeiro ◽  
Rodrigo Barros Esteves ◽  
Luís Roberto Marcondes Martins ◽  
Flávio Henrique Baggio Aguiar ◽  
...  
Keyword(s):  
Tensile Strength ◽  
Elastic Modulus ◽  
Flexural Strength ◽  
Adhesive System ◽  
Composite Resins ◽  
The Other ◽  
Adhesive Systems ◽  
Mean Values ◽  
Normality Test ◽  
Point Test

AbstractThis research aimed to evaluate the bond strength by micro tensile strength (µTBS), elastic modulus (EM) and flexural strength (FS) by the three-point test using three types of composite resins: Charisma Diamond, Filtek Z350 and Tetric N-Ceram Bulk Fill; and three adhesion techniques: adhesive, silane, silane and adhesive. The combinations of each resin with the adhesive technique resulted in nine groups (n = 12). Initially, with the composites, EM and FS tests were performed. Sequentially, each fragment was repaired with the different adhesive systems. All samples were subjected to µTBS testing on a universal assay machine. Data were subjected to the normality test and the parametric ANOVA test. Charisma resin showed the highest values in EM and RF compared to the other composite resins (p <0.05). The highest µTBS value was for silane + adhesive repaired Charisma resin. The lowest µTBS values were in Bulk Fill resin, regardless of adhesive system. The EM and FS results showed that Filtek Z350 resins had the best results, while bulk fill resins had lower results. It was concluded that Charisma and Filtek Z350 resins presented better results. However, in the bulk fill group, the lowest mean values of µTBS, FS and EM were obtained, as well as the lowest value in EM.Keywords: Composite Resins. Adhesives. Flexural Strength.ResumoEsta pesquisa teve como objetivo avaliar a resistência de união (RU) por resistência à microtração, módulo de elasticidade (ME) e resistência à flexão (RF) pelo teste de três pontos, utilizando três tipos de resinas compostas: Charisma Diamond, Filtek Z350 e Tetric N-Ceram Bulk Fill; e três técnicas de adesão: adesivo, silano, silano e adesivo. As combinações de cada resina com a técnica adesiva resultaram nove grupos (n= 12). Inicialmente, com os compósitos foram realizados testes de ME e RF. Sequencialmente, cada fragmento foi reparado com os diferentes sistemas adesivos. Todas as amostras foram submetidas ao teste de RU por microtração em uma máquina de ensaio universal. Os dados foram submetidos ao teste de normalidade e ao teste paramétrico ANOVA. A resina Charisma apresentou os maiores valores no ME e RF em relação às demais resinas compostas (p <0,05). O maior valor de RU foi para a resina Charisma reparada com silano + adesivo. Os menores valores de RU foram na resina Bulk Fill, independentemente do sistema adesivo. Os resultados no ME e RF mostraram que as resinas Filtek Z350 obtiveram os melhores resultados, enquanto as resinas bulk fill obtiveram resultados inferiores. Conclui-se que as resinas Charisma e Filtek Z350 apresentaram melhores resultados. Entretanto, no grupo de bulk fill obteve se as menores médias de RU, RF e ME, bem como o menor valor no ME.Palavras-chave: Resinas Compostas. Adesivos. Resistência à Flexão.

Stochastic Simulation of Turbine Engine Component Under Aleatory and Epistemic Uncertainty

2019 ◽  
Author(s):  
Austin M. McKeand ◽  
Recep M. Gorguluarslan ◽  
Seung-Kyum Choi
Keyword(s):  
Elastic Modulus ◽  
Epistemic Uncertainty ◽  
Element Model ◽  
Engineering Problem ◽  
Scale Model ◽  
Ct Scanner ◽  
Turbine Engine ◽  
Aleatory And Epistemic Uncertainty ◽  
Materials Used ◽  
The Given

Abstract Quantifying the uncertainty associated with material properties in engineering analysis has become more important in the design of many components in the aerospace field. In this study, a new method is proposed to account for the uncertainty associated with the elastic modulus of materials used in aerospace components. A computerized tomography (CT) scanner is used to capture the porosity of the material and the corresponding uncertainty is represented with epistemic uncertainty. A stochastic upscaling method is used to find a homogenized modulus that correctly reflects the effect of defects inside of the material. This homogenized elastic modulus is then applied to a constructed finite-element model of an aerospace component so that the stochastic behavior can be correctly quantified. Simulations of the selected example, i.e., turbine blade, include both aleatory and epistemic uncertainty; thus, a P-Box is introduced to represent the response of the simulations. The stochastic upscaling method is applied again to match the P-Box response of the coarse scale model to that of the fine scale model. The obtained results show that the proposed framework not only significantly reduces complexity of the given engineering problem, but also produces accurate results which include both aleatory and epistemic uncertainty.

scholarly journals Hydro-Thermal Fatigue of Polymer Matrix Composite Biomaterials

Materials ◽  
2019 ◽  
Vol 12 (22) ◽  
pp. 3650 ◽  
Author(s):  
Daniel Pieniak ◽  
Krzysztof Przystupa ◽  
Agata Walczak ◽  
Agata M. Niewczas ◽  
Aneta Krzyzak ◽  
...  
Keyword(s):  
Elastic Modulus ◽  
Flexural Strength ◽  
Thermal Fatigue ◽  
Bending Strength ◽  
Artificial Saliva ◽  
Filler Particle ◽  
Ceramic Composites ◽  
Inorganic Particles ◽  
Dental Restorations ◽  
Fatigue Evaluation

This study discusses a quantitative fatigue evaluation of polymer–ceramic composites for dental restorations, i.e., commercial (Filtek Z550) and experimental Ex-nano (G), Ex-flow (G). Their evaluation is based on the following descriptors: mechanical strength, elastic modulus and strain work to fracture. Supposed to reflect factors of environmental degradation conditions, thermal fatigue was simulated with a special computer-controlled device performing algorithms of thermocycling. The specimens intended for the strength test underwent 104 hydro-thermal fatigue cycles. This procedure of thermocycling was preceded by aging, which meant immersing the specimens in artificial saliva at 37 °C for 30 days. The strength tests after aging only and after aging and thermocycles were performed in line with the three-point flexural strength (TFS) test, specified in ISO 4049, and the biaxial flexural strength (BFS) test, specifically piston-on-three-ball in accordance with ISO 6872. Based on the results, it can be stated that composites with higher volume content of inorganic particles after aging only show higher strength than materials with lower filler particle content. For example, the average flexural bending strength of the Ex-flow (G) composite was about 45% lower than the value obtained for the Ex-nano (G) material. The residual strength after thermocycles is significantly lower for the experimental composites, whereas a smaller decrease in strength is recorded for the commercial composites. Decreases in strength were about 4% (Filtek Z550), 43% (Ex-nano (G)), and 29% (Ex-flow (G)) for the BFS test; and about 17% (Filtek Z550), 55% (Ex-nano (G)), 60% (Ex-flow (G)) for the TFS test. The elastic modulus of the experimental composites after only aging is higher (about 42%) than that of the commercial composite, but the elastic modulus of the commercial composite increases significantly after thermocycling. A descriptor known as strain work to fracture turns out to be a good descriptor for evaluating the hydro-thermal fatigue of the tested polymer–ceramic composites.

scholarly journals Monitoring Of Pollutants In Museum Environment

2015 ◽  
Vol 9 (2) ◽  
pp. 173-180 ◽  
Author(s):  
Budu Ana-Maria ◽  
Sandu Ion
Keyword(s):  
Organic Compounds ◽  
Inorganic Compounds ◽  
Pollution Source ◽  
Direct Reading ◽  
Inorganic Particles ◽  
Skin Cells ◽  
Art Objects ◽  
Art Works ◽  
Materials Used ◽  
Acidic Compounds

Abstract Art works are affected by environmental factors as light, temperature, humidity. Air pollutants are also implicated in their degradation. The pollution in museums has two sources: the air from outside, which brings usually dust and inorganic particles, and the inside sources – the materials used for casings (sealants, textiles placed on the display cases, varnishes, wood) that emanate organic compounds. The dust is composed of particles with a diameter of approximately 2µm or higher, which come from soil (silica) or animal and vegetal residues (skin cells, pollen). They facilitate water condensation on objects surface and biologic attack. The inorganic compounds are a result of materials combustion (SO2, NO2, NO) and in presence of water they form acidic compounds which affect the museum objects. The organic compounds are usually peroxides, acids, phthalates, formaldehyde. The effects of these pollutants are: soiling, surface discolouration, embrittlement, corrosion. Therefore, conservators are interested in monitoring the pollution degree in the display cases or in the museum air and in analyzing the effects of pollutants on the exhibited objects. They use different methods for pollutants identification, like direct reading devices based on colorimetry, that can be read after few minutes and hours (they interact with the pollutants in atmosphere), or indirect reading samples that require a laboratory. The information gathered is used for the identification of pollution source and to analyze the concentration of pollutants needed to provoke damages on the surfaces of art objects. This paper is a review of pollutants that affect the art objects and of the monitoring systems used for their identification and measuring.

Effect of Preheating and Fatiguing on Mechanical Properties of Bulk-fill and Conventional Composite Resin

2019 ◽  
Vol 45 (4) ◽  
pp. 387-395
Author(s):  
AA Abdulmajeed ◽  
TE Donovan ◽  
R Cook ◽  
TA Sulaiman
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Tensile Strength ◽  
Elastic Modulus ◽  
Flexural Strength ◽  
Composite Resin ◽  
Statistical Significance ◽  
Composite Resins ◽  
Significant Difference ◽  
Diametral Tensile Strength

Clinical Relevance Bulk-fill composite resins may have comparable mechanical properties to conventional composite resin. Preheating does not reduce the mechanical properties of composite resins. SUMMARY Statement of Problem: Bulk-fill composite resins are increasingly used for direct restorations. Preheating high-viscosity versions of these composites has been advocated to increase flowability and adaptability. It is not known what changes preheating may cause on the mechanical properties of these composite resins. Moreover, the mechanical properties of these composites after mastication simulation is lacking. Purpose: The purpose of this study was to evaluate the effect of fatiguing and preheating on the mechanical properties of bulk-fill composite resin in comparison to its conventional counterpart. Methods and Materials: One hundred eighty specimens of Filtek One Bulk Fill Restorative (FOBR; Bulk-Fill, 3M ESPE) and Filtek Supreme Ultra (FSU; Conventional, 3M ESPE) were prepared for each of the following tests: fracture toughness (International Organization for Standardization, ISO 6872), diametral tensile strength (No. 27 of ANSI/ADA), flexural strength, and elastic modulus (ISO Standard 4049). Specimens in the preheated group were heated to 68°C for 10 minutes and in the fatiguing group were cyclically loaded and thermocycled for 600,000 cycles and then tested. Two-/one-way analysis of variance followed by Tukey Honest Significant Difference (HSD) post hoc test was used to analyze data for statistical significance (α=0.05). Results: Preheating and fatiguing had a significant effect on the properties of both FSU and FOBR. Fracture toughness increased for FOBR specimens when preheated and decreased when fatigued (p=0.016). FOBR had higher fracture toughness value than FSU. Diametral tensile strength decreased significantly after fatiguing for FSU (p=0.0001). FOBR had a lower diametral tensile strength baseline value compared with FSU (p=0.004). Fatiguing significantly reduced the flexural strength of both FSU and FOBR (p=0.011). Preheating had no effect on the flexural strength of either FSU or FOBR. Preheating and fatiguing significantly decreased the elastic modulus of both composite resins equally (p&gt;0.05). Conclusions: Preheating and fatiguing influenced the mechanical properties of composite resins. Both composites displayed similar mechanical properties. Preheating did not yield a major negative effect on their mechanical properties; the clinical implications are yet to be determined.

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