Identification of organic extractables from commercial resin-modified glass-ionomers using HPLC-MS

Abstract

Elution of organic compounds from resin-based dental fillings during their application in the human mouth environment may have a potential impact on the human health. Ethanol, water and other solvents very often present in the human mouth have the ability to penetrate dental fillings placed in the human tooth. Penetration of liquids into the tooth may lead to the liberation of unreacted dental filling ingredients or their degradation products. Determination of these compounds is necessary for better knowledge from possible harmful effects caused by dental fillings. The aim of this study was the isolation and identification of compounds released from resin-modified glass-ionomer cements (RMGICs), resin-based dental materials applied in dentistry. Compounds were extracted from fillings by using four solvents (40% ethanol, water, 1% acetic acid and artificial saliva). Liquid samples containing eluted compounds were then extracted, evaporated and analyzed by using of HPLC-MS (high-performance liquid chromatography-mass spectrometry) and HPLC-DAD (high-performance liquid chromatography-diode array detection) techniques. Almost thirty components (monomers and additives) of RMGICs were identified. The main identified extractables were: Bis-GMA (bisphenol A glycidyl dimethacrylate), Bis-EMA (ethoxylated bisphenol A dimethacrylate), UDMA (urethane dimethacrylate), TEGDMA (triethylene glycol dimethacrylate), HEMA (2-hydroxyethyl methacrylate) as monomers and diphenyliodonium chloride, camphorquinone (initiators), BHA (inhibitor), 4-(dimethylamino) ethyl benzoate (co-initiator) as additives.

Quantification of organic eluates from polymerized resin-based dental restorative materials by use of GC/MS

“…The residual monomers and additives that are not chemically bond to the network are free to diffuse out from the cured materials. Several studies have shown that many of these compounds are leaching from the filling materials even after adequate polymerization [1][2][3][4][5][6][7]. It is known that some of the ingredients in the resin-based materials have cytotoxic [8][9][10][11][12][13][14], genotoxic [12,13] or allergenic effects [15][16][17][18] and/or exhibit estrogenic activity in vitro [19,20].…”

Pyrolysis-Gas Chromatography/Mass Spectrometry of Polymeric Materials

“…Lightcuring glass-ionomer cements contain polyacrylic acid, chemically and/or photo-curing monomers (multifunctional methacrylates, like triethylene glycol dimethacrylate or 2-hydroxyethyl methacrylate), an ion-leaching glass and additives (initiators, inhibitors, stabilizers and others) (Rogalewicz et al, 2006a). Resin-modified glass-ionomer cements are now widely used in dentistry as direct filling materials, liners, bases, luting cements and fissure sealants (Rogalewicz et al, 2006b). These materials mainly consist of polymer matrix and glass-ionomer parts.…”

“…These materials mainly consist of polymer matrix and glass-ionomer parts. The polymer matrix is based on a monomer system and different multifunctional methacrylates with additives (Rogalewicz et al, 2006b). Methacrylic monomers, like bisphenol A glycidyl methacrylate (Bis-GMA), urethane dimethacrylate (UDMA), triethylene glycol dimethacrylate (TEGDMA) and 2-hydroxyethyl methacrylate (HEMA) are the main components of resin-based dental filling materials.…”

“…Methacrylic monomers, like bisphenol A glycidyl methacrylate (Bis-GMA), urethane dimethacrylate (UDMA), triethylene glycol dimethacrylate (TEGDMA) and 2-hydroxyethyl methacrylate (HEMA) are the main components of resin-based dental filling materials. The presence of additives such as initiators, activators, inhibitors and plasticizers in uncured dental material mixture is necessary (Rogalewicz et al, 2006b). Figure 9 shows the total ion current Py-GC/MS chromatogram of commercially light-curing dental filling material pyrolyzed at 550 °C.…”

Casting the runes

“…Attempts at quantification have shown that elution from different materials differs significantly (Michelsen et al 2006) and the data are contradictory. Bis-GMA, Bis-EMA, UDMA and various additives have been shown to leach (Rogalewicz et al 2006), although others have failed to demonstrate BisGMA and UDMA in aqueous extracts, even though TEGDMA-based composites released high amounts of monomers (Moharamzadeh et al 2007).…”