Composites Resins
Mostrando 1-12 de 91 artigos, teses e dissertações.
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1. The use of a liner under different bulk-fill resin composites: 3D GAP formation analysis by x-ray microcomputed tomography
Abstract Gap formation of composite resin restorations is a serious shortcoming in clinical practice. Polymerization shrinkage stress exceeds the tooth-restoration bond strength, and it causes bacterial infiltration within gaps between cavity walls and the restorative material. Thus, an intermediate liner application with a low elastic modulus has been advis
J. Appl. Oral Sci.. Publicado em: 25/11/2019
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2. Influence of temperature on the adhesion of fibre reinforced polymers to timber surface
Resumo Os reforços de compósitos poliméricos com fibras de carbono (CFRP) e de vidro (GFRP) têm sido largamente usados em estruturas de madeira, onde eles podem estar expostos a condições adversas de temperatura. Para serem usados adequadamente, são necessárias informações sobre a sua adesão ao substrato. O objetivo desta pesquisa é avaliar a inf
Ambient. constr.. Publicado em: 10/06/2019
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3. Physicomechanical and thermal analysis of bulk-fill and conventional composites
Abstract The aim of this study was to evaluate the degree of conversion (DC) and the thermal stability of bulk-fill and conventional composite resins. Eleven composite resin samples were prepared to evaluate the DC, Vickers microhardness (VMH), mass and residue/particle loss, glass transition temperature (Tg), enthalpy, and linear coefficient of thermal expa
Braz. oral res.. Publicado em: 18/03/2019
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4. Effect of radiant exposure and UV accelerated aging on physico-chemical and mechanical properties of composite resins
Abstract Currently, there is no consensus in terms of defining the minimum radiant exposure values necessary for achieving adequate properties of composite resin. In addition, the long-term influence that radiant exposure has on the properties of composite resins is still questionable. Objective: The objective of this study was to evaluate the effect of radi
J. Appl. Oral Sci.. Publicado em: 07/01/2019
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5. Effect of different artificial aging protocolson fluorescence of resin composites
ABSTRACT This study evaluated the effect of different artificial aging on fluorescence of resin composites. Forty-five cylindrical specimens (6mm in diameter and 1mm thick) were made of each resin composite: IPS Empress Direct, Filtek™ Z350 XT, and Durafill. A baseline measurement of fluorescence by the direct method using the fluorescence spectrophotomete
Matéria (Rio J.). Publicado em: 06/12/2018
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6. Physicomechanical characterization and biological evaluation of bulk-fill composite resin
Abstract The aim of this study was to evaluate the cytotoxic effect, degree of conversion (% DC), Vickers hardness (VH), and surface morphology of composite resins. Eleven resins, nine bulk-fill resins, and two conventional resins were evaluated. Each material was sampled to evaluate DC (using FTIR), VH, cytotoxicity (using MTT and Neutral Red - NR test), su
Braz. oral res.. Publicado em: 25/10/2018
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7. Minimization of polymerization shrinkage effects on composite resins by the control of irradiance during the photoactivation process
Abstract High levels of shrinkage stress caused by volumetric variations during the activation process are one of the main problems in the practical application of composite resins. Objective The aim of this study is to reduce the shrinkage stress and minimize the effects caused by composite resin volumetric variation due to the photopolymerization. In thi
J. Appl. Oral Sci.. Publicado em: 18/06/2018
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8. Replacement of Commercial Silica by Rice Husk Ash in Epoxy Composites: A Comparative Analysis
Since epoxy resins are used as composite matrix with excellent results, and silica is one of the fillers most often employed, this study compared the performance of rice husk ash (RHA) as filler in epoxy composites, in replacement for high-purity silica. Composites were molded containing 20%, 40%, and 60% (wt) silica or RHA. Viscosity analysis, infrared spec
Mat. Res.. Publicado em: 05/04/2018
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9. Influence of tribological test on the global conversion of natural composites
Abstract The vinyl ester resins and natural composites have emerged as a suitable alternative in tribological application due to mechanical behavior, which relates to the conversion of the double bonds. During tribological test the permanent contact between polymeric sample and counterpart can increase the temperature affecting the crosslinking of the sample
Polímeros. Publicado em: 2017-12
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10. Should my composite restorations last forever? Why are they failing?
Abstract Composites resins have become the first choice for direct anterior and posterior restorations. The great popularity is related to their esthetic appearance and reduced need of sound tissue removal as compared with former treatments. Several studies have demonstrated that composite restorations may last long in clinical service. In this review we dis
Braz. oral res.. Publicado em: 28/08/2017
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11. Comparing depth-dependent curing radiant exposure and time of curing of regular and flow bulk-fill composites
Abstract The effect of restoration depth on the curing time of a conventional and two bulk-fill composite resins by measuring microhardness and the respective radiosity of the bottom surface of the specimen was investigated. 1-, 3- and 5-mm thick washers were filled with Surefil SDR Flow–U (SDR), Tetric EvoCeram Bulk Fill-IVA (TEC) or Esthet-X HD–B1 (EHD
Braz. oral res.. Publicado em: 21/08/2017
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12. Tensile properties and color and mass variations of GFPR composites under alkaline and ultraviolet exposures
The objective of the present study was to evaluate the influence of two different environmental conditions on the quantitative change of color and mass, tensile strength and modulus of elasticity of glass fiber reinforced polymers (GFRP) produced in Brazil. For this purpose, specimens were taken from pultruded composite profiles with two different matrices (
Matéria (Rio J.). Publicado em: 2016-03