Objective: The objective of this work was to assess the influence of storage time and pH cycling on water sorption by different composite resins.
Materials And Methods: Nine resin brands were selected and divided into groups: G1-ROK (SDI), G2-ICE (SDI), G3-GLACIER (SDI), G4-Z350 (3M/ESPE), G5-Z250 (3M/ESPE), G6-TPH 3 (DENTSPLY), G7-ESTHET X (DENTSPLY), G8-SUPRAFILL (SSWHITE), and G9-MASTERFILL (BIODINΒMICS). Ninety specimens, ten per group, were obtained using an aluminum matrix. Specimens measured 10 mm diameter × 2 mm width. The groups were divided into subgroups according to the immersion solution: A - control (n = 05) stored in artificial saliva pH = 7.0 and B-test (n = 05) submitted to seven consecutive days of pH cycling (cariogenic challenger) that consisted of immersion in a pH° = 4.3 solution for 6 h followed by immersion in a pH¹ =7.0 solution for 18 h and stored in artificial saliva pH = 7.0 until the end of the experiment. The specimens were weighed on six occasions: T 0 (after fabrication), T 1 (24 h), T 2 (7 days), T 3 (15 days), T 4 (30 days), T 5 (60 days), and then analyzed. The water sorption was determined by the weight difference between the specimens at the time intervals.
Results: The mean weight gain was exactly the same for both the subgroups within group G4. The highest means for the control subgroup were found in groups: G1, G5, G7, G8, and G9. For the pH cycling subgroup, the highest means were found in G2, G3, and G6; however, significant differences between the subgroups compared to the mean-weight gain were found for G1, G5, and G7.
Conclusion: The water sorption of composite resins is dependent upon their storage time. The pH cycling created a significant impact on resins G1, G5, and G7. The sorption and solubility of composite resins vary according to their chemical composition.
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http://dx.doi.org/10.4103/0970-9290.114954 | DOI Listing |
Anal Methods
November 2017
Guangxi Zhuang Autonomous Region Forestry Research Institute, Nanning 530002, China.
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January 2025
School of Environmental and Biological Engineering, Nanjing University of Science and Technology, Nanjing 210094, China. Electronic address:
The soils/sediments organic carbon sorption coefficient (K) of organic substances is one of the indispensable environmental behavioral parameters in chemicals management. Because the test procedure used to measure K is normally expensive and time-consuming, predictive methods are considered vitally important technology to fill the data gap of K. In this study, quantitative structure-property relationship (QSPR) models are developed using a data set with 1477 experimental logK values and seven typical machine learning algorithms.
View Article and Find Full Text PDFTalanta
January 2025
National University of Uzbekistan Named After Mirzo Ulugbek, Tashkent, 100174, Uzbekistan.
Although significant progress has been made in the effective measurement of Zn(II), Аlizarin red S (ARS) was immobilized on polyethylene polyamine-modified polyacrylonitrile (PPF-1) via a new matrix. This approach allows the detection of low levels of Zn(II) ions in various water samples via preconcentrated atomic absorption spectrometry. The use of PPF-1 in a polymer matrix for zinc preconcentration presents several advantages over traditional sorbtion-spectroscopic methods, including reduced cost, high zinc recovery, increased sensitivity, and selectivity.
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January 2025
Department of Physics and Astronomy and Thomas Young Centre, University College London, London WC1E 6BT, United Kingdom.
Atomic-scale understanding of important geochemical processes including sorption, dissolution, nucleation, and crystal growth is difficult to obtain from experimental measurements alone and would benefit from strong continuous progress in molecular simulation. To this end, we present a reactive neural network potential-based molecular dynamics approach to simulate the interaction of aqueous ions on mineral surfaces in contact with liquid water, taking Fe(II) on hematite(001) as a model system. We show that a single neural network potential predicts rate constants for water exchange for aqueous Fe(II) and for the exergonic chemisorption of aqueous Fe(II) on hematite(001) in good agreement with experimental observations.
View Article and Find Full Text PDFACS ES T Water
January 2025
School of Earth and Environmental Sciences, Queens College, City University of New York, Queens, New York 11367, United States.
Scaling minerals, such as barite, can cause detrimental consequences for oil/gas pipelines and water systems, but their formation can be inhibited by organic chelators such as ethylenediaminetetraacetic acid (EDTA). Here, we resolve how EDTA affects sorption and desorption of Pb at the barite (001) surface using a combination of X-ray scattering and microscopy measurements. In the presence of EDTA, Pb incorporated in the topmost part of the barite surface and adsorbed as inner-sphere complexes on the surface.
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