Water sorption and solubility of dental composites and identification of monomers released in an aqueous environment

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.

Surface and bulk properties of dental resin- composites after solvent storage

“…The effect of water on VHN of the investigated material can be explained by the difference in the solubility parameter of the water (48.0 ␦/MPa 1/2 ) compared to the resin-based materials. These results were in agreement with other studies comparing different solvents effect on resin-based composites [11,26,37,45,46]. Organic solvents, as Ethanol and MEK, showed more detrimental effect on the mechanical properties compared to water storage.…”

“…Organic solvents, as Ethanol and MEK, showed more detrimental effect on the mechanical properties compared to water storage. Several studies have demonstrated more complete extraction of monomers and oligomers with the organic solvents that could explain their stronger impact on the mechanical properties [8,12,45,[47][48][49][50].…”

Water sorption and solubility of bulk-fill composites polymerized with a third generation LED LCU

“…When the previous factors are standard, behavior will also be affected by the type, rate, and surface area of the filler used, the particular silane treatment, the difference in the monomer structure, and the degree of cross linking. 18 Residual monomers, fillers, degradation products or inhibitors and activators of polymerization are therefore able to leach out from cured resin-based materials. As a result, water sorption and solubility have a significant effect on the clinical success of restorative material, influencing the aesthetic appearance, integrity, and surface properties.…”

“…Water sorption and solubility studies have generally revealed that W sp and W sl values change in the same way. 25 Many researchers 16,18,26 have determined that materials with low sorption demonstrate low solubility. Some studies, however, suggest that materials with high water sorption do not necessarily demonstrate high solubility, 27 as shown here.…”

“…Negative solubility results have also been reported in other studies. 18,31,32 In some studies, these negative values have been explained by possible hydrolytic chemical reactions that result in the formation of metal hydroxides on the filler surface. 18 In other studies, it has been suggested that negative values may be the result of hydrogen bonds connecting the absorbed water molecules to polar groups of the polymer chains, which cannot be removed entirely.…”