| Contraction stress related to composite inorganic content. | |
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MedLine Citation:
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PMID: 20378161 Owner: NLM Status: MEDLINE |
Abstract/OtherAbstract:
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OBJECTIVES: The role of inorganic content on physical properties of resin composites is well known. However, its influence on polymerization stress development has not been established. The aim of this investigation was to evaluate the influence of inorganic fraction on polymerization stress and its determinants, namely, volumetric shrinkage, elastic modulus and degree of conversion. METHODS: Eight experimental composites containing 1:1 BisGMA (bisphenylglycidyl dimethacrylate):TEGDMA (triethylene glycol dimethacrylate) (in mol) and barium glass at increasing concentrations from 25 to 60 vol.% (5% increments) were tested. Stress was determined in a universal test machine using acrylic as bonding substrate. Nominal polymerization stress was obtained diving the maximum load by the cross-surface area. Shrinkage was measured using a water picnometer. Elastic modulus was obtained by three-point flexural test. Degree of conversion was determined by FT-Raman spectroscopy. RESULTS: Polymerization stress and shrinkage showed inverse relationships with filler content (R(2)=0.965 and R(2)=0.966, respectively). Elastic modulus presented a direct correlation with inorganic content (R(2)=0.984). Degree of conversion did not vary significantly. Polymerization stress showed a strong direct correlation with shrinkage (R(2)=0.982) and inverse with elastic modulus (R(2)=0.966). SIGNIFICANCE: High inorganic contents were associated with low polymerization stress values, which can be explained by the reduced volumetric shrinkage presented by heavily filled composites. |
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Authors:
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F Gonçalves; Y Kawano; R R Braga |
Publication Detail:
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Type: Journal Article; Research Support, Non-U.S. Gov't Date: 2010-04-07 |
Journal Detail:
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Title: Dental materials : official publication of the Academy of Dental Materials Volume: 26 ISSN: 1879-0097 ISO Abbreviation: Dent Mater Publication Date: 2010 Jul |
Date Detail:
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Created Date: 2010-05-31 Completed Date: 2010-09-22 Revised Date: - |
Medline Journal Info:
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Nlm Unique ID: 8508040 Medline TA: Dent Mater Country: England |
Other Details:
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Languages: eng Pagination: 704-9 Citation Subset: D |
Copyright Information:
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Copyright 2010 Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved. |
Affiliation:
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Department of Dental Materials, School of Dentistry, University of São Paulo, São Paulo, SP, Brazil. fgoncalves@usp.br |
Export Citation:
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APA/MLA Format Download EndNote Download BibTex |
| MeSH Terms | |
Descriptor/Qualifier:
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Analysis of Variance Barium Compounds Bisphenol A-Glycidyl Methacrylate Composite Resins / chemistry*, radiation effects Dental Bonding, Light-Cured Dental Marginal Adaptation* Dental Stress Analysis Elastic Modulus Hardness Inorganic Chemicals Materials Testing Particle Size Phase Transition Pliability Polyethylene Glycols Polymethacrylic Acids Regression Analysis Silicon Dioxide Spectroscopy, Fourier Transform Infrared |
| Chemical | |
Reg. No./Substance:
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0/Barium Compounds; 0/Composite Resins; 0/Inorganic Chemicals; 0/Polyethylene Glycols; 0/Polymethacrylic Acids; 0/barium glass filler; 109-16-0/triethylene glycol dimethacrylate; 1565-94-2/Bisphenol A-Glycidyl Methacrylate; 7631-86-9/Silicon Dioxide |
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine
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