In this study, a new biobased isosorbide urethane methacrylic monomer [isosorbide‐derived urethane dimethacrylate (Is‐UDMA)] was evaluated as a replacement for currently used bisphenol A glycerolate dimethacrylate (Bis‐GMA) based dental restorative materials. Dental composites were prepared at different Is‐UDMA and Bis‐GMA concentrations. For these composites, the photocuring kinetics, volumetric shrinkage, viscoelastic properties, water sorption, and solubility were evaluated. The photocuring kinetics, followed by real‐time IR spectroscopy, showed higher double‐bond conversion (DC) values for the formulations containing the Is‐UDMA monomer; the highest DC (82%) was achieved by the formulation prepared with only the Is‐UDMA monomer. The volumetric shrinkage was reduced to 23.7% as compared with the dental resin formulated with Bis‐GMA. The viscoelastic properties of the formulations containing both Is‐UDMA and Bis‐GMA monomers in a 50:50 composition were superior to the rest of the tested formulations, including those prepared with pure polymers. This behavior was explained in terms of a compromise between crosslinking and rigidity (or flexibility) of the resulting polymer network. A preliminary test on microleakage in a dental enamel demonstrated that the new Is‐UDMA monomer is a potential replacement for the Bis‐GMA monomer in dental restorative materials. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 44591.
In this work, the synthesis of two new antishrinking methacrylic monomers of spiroorthocarbonate type, SOC‐IP‐UDMA and SOC‐UDMA, is discussed, along with studies of their performance as polymeric matrix in dental composites. The monomers were photoactive with components of a conventional resin composite. In order to study the photocuring kinetics of these SOC monomers, a real‐time test was performed using FTIR spectroscopy. It was found that SOCs promoted higher double bond conversions (DC) than conventional methacrylic monomer bis‐GMA (48%), reaching a DC value of 68% for SOC‐UDMA and 75% for SOC‐IP‐UDMA. The shrinkage stress that accompanies curing of dental composites was measured by a universal testing machine. These new monomer SOCs are capable of reducing the shrinkage up to 51.1% and 27.7% for both methacrylic monomers when they were compared with bis‐GMA as control. Also, a dynamical mechanical analysis was conducted on the dental composites, obtaining a higher modulus and a range of T g values from 80 to 100 °C. Others parameters like flexural properties, solubility, and sorption water were determined, obtaining values better than or equal to the parameters established by the standard ISO 4049. These monomers can be considered as alternative matrixes to replace bis‐GMA in dental composites. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 136, 47114.
In this work was evaluated the efficiency of an antishrinkage additive in a dental resin. This additive was a mixture 1:1 of five and six-membered ring spiroorthocarbonates functionalized with allylic groups (SOC DA). The aim of this study was to reduce the shrinkage of a typical dental resin composed of a blend of the dimethacrylates, Glycerolate bisphenol A dimethacrylate (Bis-GMA)/2-[(3,5,5-trimethyl-6-[2-(2-methyl prop-2-enoyloxy) ethoxycarbonylamino] hexyl) carbamoyloxy] ethyl, 2-methyl prop-2-enoate, (UDMA)/triethyleneglycol dimethacrylate (TEGDMA) in a 50:30.20 molar ratio, and silicon dioxide as filler. SOC DA was added at 5, 10 and 20 mol% to the already mentioned formulation. It was found that the addition of 20 mol% of SOC DA decreased 53 % the shrinkage of the cured composite material, in comparison with a formulation where it was not added the antishrinkage additive. Besides, the kinetics of photopolymerization determined by Real-Time infrared spectroscopy, demonstrated that the addition of increasing concentration of SOC DA improved the conversion of double bonds of dimethacrylates. Additionally, the presence of SOC DA at 10 % mol, helped to increase the flexural strength and the compressive strength of the composite, as a consequence of the augment of the crosslink density, induced by the ring opening polymerization of SOC DA.
Shape memory polymers (SMPs) are stimuli‐response materials known for their ability to be actuated from temporary shape into original shape. Because of this unique functionality SMPs are promising materials for diverse applications fields, including smart biomedical devices, aviation, automobile, structures or coatings. In this article, the work has been focused on the chemical modification of an epoxy monomer Bisphenol A diglycidyl ether (DGEBA) which was carried out by using allyl amines as curing agents and a thiol. When both systems Epoxy‐Amine/Tiol‐Ene were photopolymerized, a soft phase is introduced through a thiol‐ene system and a rigid phase is given by the polymerization of the epoxy polymer when it reacts with the curing agent allyl amine. One of the main requirements in SMPs is the presence of soft and rigid phases. The study of the effect of the concentration of three different curing agents, allyl amine type, over the capacity of the conformed polymers to return to their original shape was evaluated. DMA analysis was used to determine the Tg in the polymers, once obtained, the polymers were treated on a hot water bath above 10 °C their Tg, then the evaluation of the memory shape was carried out by two tests, bending and torsion. SMPs were obtained and specimens with 20% of concentration of allyl amine as curing agent showed an improvement in their ability of memory shape with a 99% of recovery.
In this work is discussed the synthesis of a novel antishrinking agent (SOC DA) and the evaluation of its performance in an acrylic dental resin. SOC DA was photopolymerized in conjunction with the components of a conventional acrylic resin, which includes a mixture of diacrylate monomers [glycerolate bisphenol A dimethacrylate (BIS-GMA) / Urethane dimethacrylate (UDMA) / triethyleneglycol dimethacrylate (TEGDMA)] in 50/30/20 molar ratio). SOC DA was added in a range between 5.0-20.0 mol % with respect to the total amount of moles of the acrylic monomers. It was found that increasing concentrations of SOC DA, promoted higher conversions of the dimethacrylate monomers without decreasing the photopolymerization rate of the acrylate monomers. The study of the effect of SOC DA on the mechanical properties of the dental composite filled with 70 % of silicon dioxide, revealed that the presence of the antishrinking agent improved both the compressive and the flexural strength of the dental materials. Besides, it was found that by using the SOC DA at 20%, the shrinkage was reduced 52%, compared with the same formulation without SOC DA.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.