Synthesis and Characteristics of Dental Composites with Novel Bis-GMA Derivate as a Resin Base

Abstract

2,2-bis [4-(2-hydroxy-3-methacryloyloxypropoxy) pheny propane (Bis-GMA) and triethylene glycol dimethacrylate (TEGDMA) have been commonly used as a viscous monomer and a reactive diluent in the organic phase of dental restorative composites, respectively. The purpose of addition of TEGDMA is mainly to decrease the high viscosity of Bis-GMA caused by hydrogen bonding between hydroxyl groups. However, some adverse effects will accompany with increased amounts of the TEGDMA, such as higher values of polymerization shrinkage, which is not undesirable for the clinical application. Therefore, substituting hydroxyl groups of Bis-GMA might be an appropriate and effective way to reduce the amount of diluents and weaken the accompanied adverse effects. This work focuses on the synthesis of a novel Bis-GMA derivate, substituting acetyl groups for hydroxyl groups in Bis-GMA. The viscosity of Bis-GMA characterized with rotational rheometer was significantly decreased from 820 Pa.s to 11 Pa.s by substitution of acetyl group, leading to the low amount of TEGDMA in resin matrix. Differential Scanning Calorimeter (DSC) was used for investigating the reaction kinetics of this novel monomer with different mass ratios of TEGDMA. The results suggested that the maximum conversion of the Ac-Bis-GMA can reach 88% while the corresponding value for Bis-GMA is 75%. Dental composites were prepared from 2,2-bis [4-(2-acetyl-3-methacryloyloxypropoxy) pheny propane (Ac-Bis-GMA) or Bis-GMA resin mixtures with TEGDMA filled with 70 wt% silica co-fillers. The results presented that dental composites prepared from new resin matrixes exhibited adequate mechanical properties.

Design and characterisation of dental resin restorative composites with Ac-Bis-GMA and bimodal silica nanostructures

“…3,9 Bimodal silica nanostructures including SiO 2 NPs and SiO 2 NCs were prepared with the Stö ber method and the coupling reaction, respectively, according to the reported method. 8,10,11 All inorganic fillers were silanized with c-MPS to introduce cross-linkable vinyl groups on their surface so as to improve the interfacial adhesions with the resin matrix.…”

“…Besides, RBC 58-12 (filler loading: 70 wt-%, commercial micro-SiO 2 :nano-SiO 2 558:12 wt/wt) was served as control so as to investigate the effect of filler compositions on properties of resin composites. 2,3,14 Characterization Degree of conversion Degree of conversion of resin composites was evaluated with a FTIR spectrometer equipped with an ATR crystal (Nicolet 8700, Bruker Optik GmbH, Germany), operating with 32 scans at a resolution of 4 cm 21 , which was determined from the ratio of absorbance intensities of aliphatic CvC bond (1638 cm 21 ) against aromatic CvC bond (1608 cm 21 ) before and after curing of each specimen. 15 Three independent runs were performed for each resin composite.…”

“…2 The application of the diluent, such as tri(ethylene glycol) dimethacrylate (TEGDMA), can overcome the high viscosity of Bis-GMA, causing by the intermolecular hydrogen bonding between hydroxyl groups in its structure, which also brings some adverse effects, such as the increased polymerization shrinkage (PS) and the higher water sorption, resulting in the shorter life span of restorative resin composites. 3 Extensive research work has been performed to design Bis-GMA derivates with lower viscosity, so as to reduce the amount of diluent and minimise its negative effect. [3][4][5][6][7] In the published research work of authors, acetyl-substituted Bis-GMA derivate (Ac-Bis-GMA) was synthesised by the facile esterification reaction, which was used with less amount of TEGDMA and commercial microsize and nanosize (M/N) SiO 2 particles to fabricate dental resin composites, leading to the reduction of PS to 2?8%.…”

“…3 Extensive research work has been performed to design Bis-GMA derivates with lower viscosity, so as to reduce the amount of diluent and minimise its negative effect. [3][4][5][6][7] In the published research work of authors, acetyl-substituted Bis-GMA derivate (Ac-Bis-GMA) was synthesised by the facile esterification reaction, which was used with less amount of TEGDMA and commercial microsize and nanosize (M/N) SiO 2 particles to fabricate dental resin composites, leading to the reduction of PS to 2?8%. 2,3 However, given to the extended longevity of restorations, the shrinkage value should still be decreased further, which could be considered and designed from the inorganic fillers.…”

“…[3][4][5][6][7] In the published research work of authors, acetyl-substituted Bis-GMA derivate (Ac-Bis-GMA) was synthesised by the facile esterification reaction, which was used with less amount of TEGDMA and commercial microsize and nanosize (M/N) SiO 2 particles to fabricate dental resin composites, leading to the reduction of PS to 2?8%. 2,3 However, given to the extended longevity of restorations, the shrinkage value should still be decreased further, which could be considered and designed from the inorganic fillers. Based on the authors' previous work, the introduction of bimodal silica nanostructures comprising SiO 2 NPs and SiO 2 NCs could be an effective gateway to regulate the interparticle distance, the filler packing density, and the light permeability, leading to the decreased PS, improved wear resistance, and degree of conversion (DC).…”