This study analyzed the relationship between the degree of conversion (DC), solubility, and salivary sorption of a hybrid (Filtek P 60) and a nanofilled resin composite (Filtek Supreme), and evaluated the influence of the light-activation mode on these properties. Two light-activation modes were used: Conventional (C; 850 mW/cm(2) for 20 s) and Soft-start (SS; 100-1,000 mW/cm(2) for 10 s + 1,000 mW/cm(2) for 10 s). The DC (%) was evaluated by FT-Raman spectroscopy. The solubility and salivary sorption were measured after immersion in artificial saliva for 7 days. Data were analyzed by ANOVA and Student-Newman-Keuls' test and linear regression analysis (a = 0.05). The DC varied from 50.52% (nanofilled composite) to 57.15% (hybrid composite), and was influenced by the light-activation mode: C > SS. The solubility (0.45 microg/mm(3)) and salivary sorption (8.04 microg/mm(3)) of the nanofilled composite were greater than those of the hybrid composite (0.40 microg/mm(3) / 6.87 microg/mm(3)), and were influenced by the light-activation mode: SS > C. Correlation was found between DC and solubility (r = - 0.89, p<0.05), as well as between solubility and salivary sorption (r = 0.95). These findings suggest that nanofilled composites may present higher degradation in the oral environment than hybrid ones. Soft-start light-activation mode may increase the solubility of resin composites.
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http://dx.doi.org/10.1590/s1678-77572008000200015 | DOI Listing |
Dent Mater
October 2024
Institute of Biomedical Engineering, University of Toronto, Ontario, Canada; Faculty of Dentistry, University of Toronto, Canada; Translational Biology and Engineering Program, University of Toronto, Canada; Department of Chemical Engineering and Applied Chemistry, University of Toronto, Canada. Electronic address:
Objective: The biodegradation of methacrylate (MA)-based dental restoratives has been suggested to contribute to a loss of adhesion and subsequent detachment, or secondary caries, both major causes of restoration failure. Previous studies have demonstrated that intermolecular interactions between resin monomers may affect the hydrolytic-susceptibility of composites. Altering the intermolecular interactions by shielding or masking the hydrolytically-susceptible ester groups found in MA monomers could be an effective strategy to mitigate the biodegradation of resin composites.
View Article and Find Full Text PDFJ Dent
September 2024
Department of Orthodontics, Institute of Craniofacial Deformity, Yonsei University College of Dentistry, Seoul, Republic of Korea. Electronic address:
Objectives: To create bacteria-resistant dental CAD-CAM blocks with a biofilm-resistant effect by incorporating Nano-crystalline ceramic and polymer (NCP) with 2-methacryloyloxyethyl phosphorylcholine (MPC) and sulfobetaine methacrylate (SBMA) and at an equimolar ratio, referred to as MS.
Methods: Experimental groups comprised NCP blocks containing zwitterions at 0.15wt% (MS015) and 0.
Membranes (Basel)
July 2023
Kurnakov Institute of General and Inorganic Chemistry, Russian Academy of Sciences, 119991 Moscow, Russia.
The development of accessible express methods to determine markers of viral diseases in saliva is currently an actual problem. Novel cross-sensitive sensors based on Donnan potential with bio-comparable perfluorosulfonic acid membranes for the determination of salivary viral markers (-acetyl--methionine, -carnitine, and -lysine) were proposed. Membranes were formed by casting from dispersions of Nafion or Aquivion in -methyl-2-pyrollidone or in a mixture of isopropyl alcohol and water.
View Article and Find Full Text PDFInt J Mol Sci
September 2022
Faculty of Chemistry, Lomonosov Moscow State University, 119991 Moscow, Russia.
Nano- and microparticles enter the body through the respiratory airways and the digestive system, or form as biominerals in the gall bladder, salivary glands, urinary bladder, kidney, or diabetic pancreas. Calcium, magnesium, and phosphate ions can precipitate from biological fluids in the presence of mucin as hybrid nanoparticles. Calcium carbonate nanocrystallites also trap mucin and are assembled into hybrid microparticles.
View Article and Find Full Text PDFDent Mater
February 2022
Department of Surgical and Developmental Sciences, School of Dentistry, University of Minnesota, Moos Health Science Tower, 515 Delaware Street S.E., Minneapolis, MN 55455, USA. Electronic address:
Objective: The region of failure for current methacrylates (i.e. derivatives of acrylates) are ester bond linkages that hydrolyze in the presence of salivary and bacterial esterases that break the polymer network backbone.
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