Polymerization Stress
Mostrando 1-12 de 81 artigos, teses e dissertações.
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1. Influence of Modulated Photo-Activation on Shrinkage Stress and Degree of Conversion of Bulk-Fill Composites
Resumo O presente estudo teve como objetivo avaliar as propriedades de polimerização de materiais bulk-fill (baixa e alta viscosidade) utilizando luz contínua de alta intensidade e fotoativação intermitente em relação ao estresse de contração de polimerização e grau de conversão (DC). As seguintes resinas compostas Bulk-fill e nanohíbridas conve
Braz. Dent. J.. Publicado em: 28/11/2019
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2. 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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3. Shrinkage stress and elastic modulus assessment of bulk-fill composites
Abstract Bulk-fill composites were introduced in dentistry to accelerate clinical procedures while providing adequate outcomes. Concerns regarding the use of bigger composite increments rely on the polymerization shrinkage and shrinkage stress, which may generate gaps on the adhesive interface and result in a reduced success rate. Objective: To evaluate the
J. Appl. Oral Sci.. Publicado em: 07/01/2019
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4. Effect of hydroxyurea (HU) on gelatinization mechanism of type I collagen suspensions
ABSTRACT Mutant hemoglobins thermodynamic phase transitions (HbS, HbC, etc.) have been the causes of serious hemoglobinopathies that have been affecting mankind since the dawn of human race. HbS polymerization is the best known of these transitions and the original cause of sickle cell anemia. Hydroxyurea (HU, NH2CONHOH) is widely used as the main drug admin
Matéria (Rio J.). Publicado em: 06/12/2018
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5. 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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6. Polymerization shrinkage stress of composite resins and resin cements – What do we need to know?
Abstract Polymerization shrinkage stress of resin-based materials have been related to several unwanted clinical consequences, such as enamel crack propagation, cusp deflection, marginal and internal gaps, and decreased bond strength. Despite the absence of strong evidence relating polymerization shrinkage to secondary caries or fracture of posterior teeth,
Braz. oral res.. Publicado em: 28/08/2017
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7. Optimizing light-cured composite through variations in camphorquinone and butylhydroxytoluene concentrations
Abstract The use of a free-radical polymerization inhibitor, butylhydroxytoluene (BHT), and a common photo-initiator, camphorquinone (CQ), to reduce polymerization stress in dental composite was investigated in this study. Samples were prepared by mixing Bis-GMA, UDMA, and TEGDMA at a 1:1:1 ratio (wt%), and silanized borosilicate glass fillers at 70 wt% were
Braz. oral res.. Publicado em: 20/05/2016
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8. Marginal integrity of restorations produced with a model composite based on polyhedral oligomeric silsesquioxane (POSS)
Marginal integrity is one of the most crucial aspects involved in the clinical longevity of resin composite restorations. Objective To analyze the marginal integrity of restorations produced with a model composite based on polyhedral oligomeric silsesquioxane (POSS). Material and Methods A base composite (B) was produced with an organic matrix with UDMA/
J. Appl. Oral Sci.. Publicado em: 2015-10
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9. Influence of polymeric matrix on the physical and chemical properties of experimental composites
Nowadays, the main reasons for replacement of resin-based composite restorations are fracture or problems with the integrity of their interface, such as marginal staining, microleakage, or secondary caries. The aim of the present study was to evaluate the influence of the organic matrix on polymerization stress (PS), degree of conversion (DC), elastic modulu
Braz. oral res.. Publicado em: 2015
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10. EFEITO DA FOTOATIVAÇÃO PROLONGADA DE ADESIVOS AUTOCONDICIONANTES NA ADESÃO À DENTINA / Effect of prolonged exposure time of one-step self-etching in dentinbonding
This study evaluated the effect of prolonged exposure times on immediate (IM) and 6-month (6M) adhesive properties: degree of conversion within hybrid layer (DC), silver nitrate uptake (SNU) and resin-dentin bond strenght (μTBS) for three one-step self-etch adhesive systems (Adper Easy Bond [EB], Clearfil S3 Bond [CS3] and Go [GO]).Ninety caries-free ex
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 24/02/2012
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11. The influence of "C-factor" and light activation technique on polymerization contraction forces of resin composite
OBJECTIVES: This study evaluated the influence of the cavity configuration factor ("C-Factor") and light activation technique on polymerization contraction forces of a Bis-GMA-based composite resin (Charisma, Heraeus Kulzer). MATERIAL AND METHODS: Three different pairs of steel moving bases were connected to a universal testing machine (emic DL 500): groups
J. Appl. Oral Sci.. Publicado em: 2012-12
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12. Photoelastic evaluation of the effect of composite formulation on polymerization shrinkage stress
We compared polymerization stress in two commercial composites and three experimental composites made using camphorquinone (CQ) and/or phenylpropanedione (PPD) as photoinitiators. The internal surfaces of photoelastic resin discs with cylindrical cavities were roughened and treated with adhesive. Composites were divided into five groups: two commercial compo
Brazilian Oral Research. Publicado em: 2012-06