Organic leachables from polymer‐based dental filling materials

Abstract

Results are reported from a study on the in vitro separation and identification of leachables from three different polymer-based dental filling materials by using a combined method of gas chromatography and mass spectrometry. The median number of separable organic leachables in these materials was between 14 and 22. Of these organic leachables the following were identified and quantified: DL-camphorquinone, 4-dimethylaminobenzoic acid ethyl ester (DMABEE), drometrizole, 1,7,7-trimethylbicyclo[2,2,1]heptane, 2,2-dimethoxy[1,2] diphenyletanone (DMBZ), ethyleneglycol dimethacrylate (EGDMA), and triethyleneglycol dimethacrylate (TEGDMA). Three of the leachables have previously been shown to provoke allergy. The range of log P(ow) values (representing the lipophilicity of these compounds) varied between 1.09 and 4.20. By multivariate data analysis, selected leachables from the tested materials were shown to separate into characteristic patterns. The results contribute to a characterization of potential hazardous compounds in polymer-based dental filling materials.

Identification and quantification of monomers released from dental composites using HPLC

“…The desiccation of specimens at 37°C was carried out until a constant mass was achieved, and this period could have allowed the post-polymerization of the composites, increasing the degree of conversion and reducing the amount of unreacted monomers (Pearson and Longman, 1989;Ferracane, 1994;Lygre et al, 1999;Ferracane, 2006). A recent study (Mortier et al, 2005) evaluated the solubility of different dental composites with and without initial dehydration and found values up to 8-times higher for specimens not previously desiccated.…”

“…Despite of being considered highly stable structures, dental composites are susceptible to degradation (Geurtsen, 1998) due to the incomplete polymerization and the influence of the aqueous oral environment (Oysaed and Ruyter, 1986). When a composite material is immersed in water, some of the components, such as unreacted monomers (Inoue and Hayashi, 1982;Oysaed et al, 1988;Tanaka et al, 1991;Ferracane, 1994;Örtengren et al, 2001), filler particles (Söderholm, 1983) and other components (Lygre et al, 1999) are leached out of the material. This can be assessed as solubility or leaching.…”

Effect of dual-peak LED unit on the polymerization of coinitiator-containing composite resins

“…Like CQ, if some portion of amines remains residually, they can cause discoloration of the host composite resins. To overcome the drawbacks of CQ, addition of extra photoinitiator such as 2,2-dimethoxy [1,2] diphenyletanone (DMBZ), 1-phenyl-1,2-propanedione (PPD), and diphenyl (2,4,6-trimethylbenzoyl) phosphine oxide (TPO) has been proposed as a coinitiator [5][6][7][8] . According to the recent studies through the systemic evaluation of microhardness using the various narrow band fi ltered lights, some composite resins are conjectured to contain one of these coinitiators 9) .…”

Casting the runes

“…Most information on the release of material components is based on laboratory models with solvents such as ethanol, water, saline, artificial saliva or culture media. Gas chromatography and mass spectrometry of the solutes from composites, compomers and resin based glass-ionomers have demonstrated the presence of a number of organic leachables such as monomers, co-monomers, initiators, stabilizers, decomposition products and contaminants Some of them have been identified as the low viscosity monomers EDGMA, TEGDMA and HEMA together with initiator and co-initiators such as hydroquinone, camphorquinone, and DMABEE and an ultraviolet absorber, Tinuvin P (Lygre et al 1999, Michelsen et al 2003). Attempts at quantification have shown that elution from different materials differs significantly (Michelsen et al 2006) and the data are contradictory.…”