Residual Monomer/Additive Release and Variability in Cytotoxicity of Light-curing Glass-ionomer Cements and Compomers

Abstract

In previous studies, light-cured glass-ionomer cements have been shown to evoke cytotoxic reactions. It was the purpose of this investigation (a) to determine the nature of the ingredients released into an aqueous medium from 2 light-cured glass-ionomer cements (GICs) and 3 compomers; (b) to evaluate the cytotoxicity of these extracts; and (c) to correlate the extent of the cytotoxic effects with eluted substances. Specimens of 2 light-cured GICs and 3 compomers were prepared and extracted in distilled water or cell culture medium for 24 hrs (surface-liquid ratio 42.4 mm2/mL). The aqueous eluates were analyzed by gas chromatography/mass spectrometry (GC/MS). The relative amounts of the components released from various products were compared by means of an internal caffeine standard [%CF]. For evaluation of cytotoxic effects, permanent 3T3 fibroblasts were incubated with medium extracts for 24 hrs. In addition, the ED50 concentration of the photoinitiator diphenyliodoniumchloride (DPICl) was determined. In all extracts, several water-elutable organic substances were found: (Co)monomers (especially HEMA and ethylene glycol compounds), additives (e.g., camphorquinone and diphenyliodoniumchloride), and decomposition products. The extracts of 3 products inhibited cell growth only moderately, whereas the light-cured GIC Vitrebond and the compomer Dyract Cem revealed severe cytotoxic effects. Vitrebond liberated the initiator DPICl, whereas Dyract Cem segregated a relatively high quantity [2966 %CF] of the comonomer TEGDMA in comparison with the other products. The present data show that TEGDMA and DPICl may be regarded as the prime causes for cytotoxic reactions evoked by the investigated light-cured glass-ionomer cements or compomers. Therefore, leaching of these substances should be minimized or prevented.

Influence of Different Concentration and Ratio of a Photoinitiator System on the Properties of Experimental Resin Composites

“…An inadequate polymerization affects biocompatibility due to the release of monomers that may damage cells in oral tissues (21). This would argue for higher CQ/amine concentrations to maximize cure.…”

The role of poly(acrylic acid) in conventional glass polyalkenoate cements

“…In general, CGPCs do not pose an acute systemic risk or chronic toxic behavior; however, it is important to assess their systemic toxicity prior to their market launch. A number of studies [100][101][102][103][104][105] intensively investigated the cytotoxicity of CGPCs. It was consistently illustrated that the cytotoxic behavior of CGPCs depends on their setting reaction.…”

Evaluation of cytotoxic effects of six self-etching adhesives with direct and indirect contact tests

“…Major monomers and co-monomers have been identified as the cytotoxic components of the organic matrix of resin composite materials, and a relationship between the structural and biological activities of monomers has been reported 14,15) . Two-hydroxyethyl methacrylate (HEMA), triethyleneglycol dimethacrylate (TEGDMA), bisphenol A-glycidyl-methacrylate (Bis-GMA), and urethane dimethacrylate (UDMA) are common constituents of restorative materials and have been identified in aqueous extracts from cured resin restoratives 16,17) . Several in vitro studies have shown that HEMA and Evaluation of cytotoxic effects of six self-etching adhesives with direct and indirect contact tests TEGDMA have cytotoxic potentials 18,19) to a lesser degree than the more hydrophobic monomers Bis-GMA or UDMA 9) .…”