Water sorption and solubility of dental composites and identification of monomers released in an aqueous environment
TL;DR: Water sorption and solubility of six proprietary composite resin materials were assessed, and monomers eluted from the organic matrix during water storage identified, and triethyleneglycol dimethacrylate was the main monomer released.
Abstract: Water sorption and solubility of six proprietary composite resin materials were assessed, and monomers eluted from the organic matrix during water storage identified. Water sorption and solubility tests were carried out with the following storage times: 4 h, 24 h and 7, 60 and 180 days. After storage, water sorption and solubility were determined. Eluted monomers were analysed by high performance liquid chromatography (HPLC). Correlation between the retention time of the registered peak and the reference peak was observed, and UV-spectra confirmed the identity. The results showed an increase in water sorption until equilibrium for all materials with one exception. The solubility behaviour of the composite resin materials tested revealed variations, with both mass decrease and increase. The resin composition influences the water sorption and solubility behaviour of composite resin materials. The HPLC analysis of eluted components revealed that triethyleneglycol dimethacrylate (TEGDMA) was the main monomer released. Maximal monomer concentration in the eluate was observed after 7 days. During the test period, quantifiable quantities of urethanedimethacrylate (UEDMA) monomer were observed, whereas 2,2-bis[4-(2-hydroxy-3-methacryloyloxypropoxy)-phenyl]propane (Bis-GMA) was only found in detectable quantities. No detectable quantities of bisphenol-A were observed during the test period.
Citations
More filters
TL;DR: Dental polymer networks have been shown to be susceptible to hygroscopic and hydrolytic effects to varying extents dependent upon their chemistry and structure, and these effects on the clinical performance of polymer restoratives is largely unknown.
1,190 citations
Cites background from "Water sorption and solubility of de..."
...[34] compared the water uptake of a variety of composites and resin cements for up to 6 months....
[...]
TL;DR: A meta-analytical study on the short and long-term release of components from resin-based dental materials, and how much (order of magnitude) of those components may leach out in the oral cavity is presented in this paper.
323 citations
01 Jan 2013
TL;DR: This meta-analytical study reviewed the literature on the short- and long-term release of components from resin-based dental materials, and to determine how much of those components may leach out in the oral cavity.
Abstract: OBJECTIVES
Resin-based dental materials are not inert in the oral environment, and may release components, initially due to incomplete polymerization, and later due to degradation. Since there are concerns regarding potential toxicity, more precise knowledge of the actual quantity of released eluates is necessary. However, due to a great variety in analytical methodology employed in different studies and in the presentation of the results, it is still unclear to which quantities of components a patient may be exposed. The objective of this meta-analytical study was to review the literature on the short- and long-term release of components from resin-based dental materials, and to determine how much (order of magnitude) of those components may leach out in the oral cavity.
METHODS
Out of an initial set of 71 studies, 22 were included. In spite of the large statistical incertitude due to the great variety in methodology and lack of complete information (detection limits were seldom mentioned), a meta-analytical mean for the evaluated eluates was calculated. To relate the amount of potentially released material components with the size of restorations, the mean size of standard composite restorations was estimated using a 3D graphical program.
RESULTS
While the release of monomers was analyzed in many studies, that of additives, such as initiators, inhibitors and stabilizers, was seldom investigated. Significantly more components were found to be released in organic than in water-based media. Resin-based dental materials might account for the total burden of orally ingested bisphenol A, but they may release even higher amounts of monomers, such as HEMA, TEGDMA, BisGMA and UDMA. Compared to these monomers, similar or even higher amounts of additives may elute, even though composites generally only contain very small amounts of additives. A positive correlation was found between the total quantity of released eluates and the volume of extraction solution.
SIGNIFICANCE
There is a clear need for more accurate and standardized analytical research to determine the long-term release from resin-based materials. Several guidelines for standardization are proposed.
317 citations
Cites background or methods from "Water sorption and solubility of de..."
...Gravimetrical measurement of a composite sample before nd after extraction of components is the least expensive ethod [17,19,73,76,77] and indicated that depending on the xtracting solvent, up to 10–11 wt% can be extracted from esin-based restorative materials [17,78–80]....
[...]
...because they assessed the release in a qualitative way (detected or not detected) [73,87,88] or in a semi-quantitative manner....
[...]
...[73] after 6 months, Polydorou et al....
[...]
TL;DR: Chairside silica coating and silanization provided higher resin-resin bond strength values compared to acid etching with phosphoric acid followed by adhesive resin applications and Citric acid was the least aggressive aging medium.
237 citations
Cites background from "Water sorption and solubility of de..."
...The progressive degradation of the microstructure occurs by the formation of pores, in which oligomers, residual monomers, products of degradation and additives may be released [4,5]....
[...]
...Composites may suffer from chemical degradation and erosion depending on the composition of monomers, polymerization of the matrix, degree of conversion and the oral environment [4,5]....
[...]
...[5] revealed that TEGDMA was the most released monomer....
[...]
TL;DR: In this article, the elution of residual monomers from light-cured dental resins and resin composites into a 75% ethanol:water solution was studied using High-Performance Liquid Chromatography (HPLC).
Abstract: In the present work the elution of residual monomers from light-cured dental resins and resin composites into a 75% ethanol:water solution was studied using High-Performance Liquid Chromatography (HPLC). The resins studied were made by light-curing of bisphenol A glycol dimethacrylate (Bis-GMA), triethylene glycol dimethacrylate (TEGDMA), urethane dimethacrylate (UDMA), ethoxylated bisphenol A glycol dimethacrylate [Bis-EMA(4)] and mixtures of these monomers. The resin composites were made from two commercial light-cured restorative materials (Z100 MP and Filtek Z250), the resin matrix of which is based on copolymers of these monomers. The effect of the curing time on the amount of monomers eluted was investigated. The concentration of the extractable monomers was determined at several immersion periods from 3 h to 30 days. For all the materials studied, it was observed that the chemical structure of the monomers used for the preparation of the resins, which defines the chemical and physical structure of the corresponding resin, directly affects the amount of eluted monomers, as well as the time needed for the elution of this amount. In the case of composites, it seems that the elution process it is not influenced by the presence of filler.
235 citations