Long‐term release of monomers from modern dental‐composite materials

Abstract

The elution of monomers from composite materials influences the biocompatibility of dental restorations. The purpose of the present study was to investigate the elution of monomers [bisphenol A glycidyl methacrylate (BisGMA), triethylene glycol dimethacrylate (TEGDMA), urethane dimethacrylate (UDMA), and bisphenol A (BPA)] from two light-cured materials (nanohybrid and ormocer) and from a chemically cured composite material, after different curing times (0, 20, 40 and 80 s) and different storage periods (24 h, 7 d, 28 d, and 1 yr after curing). Each specimen was stored in 1 ml of 75% ethanol. This medium was renewed after 24 h, 7 d, 28 d, and 1 yr. The ethanol samples were analyzed using liquid chromatography tandem mass spectrometry (LC-MS/MS). The amount of monomers released from the nanohybrid and the chemically cured composite was significantly higher than released from the ormocer. The curing time exerted a significant effect on the release of monomers. For the nanohybrid, less monomer was released after increasing the curing time. For the ormocer, 80 s of curing resulted in a higher degree of monomer release. The effect of storage differed between the monomers. Although the elution of TEGDMA was significantly decreased after storage for 28 d and 1 yr, a similar amount of BisGMA was released at each storage time-point analyzed, even after 1 yr. The present study showed that ormocer released a very small amount of monomers compared with the other materials.

Concomitant contact allergy to formaldehyde and methacrylic monomers in students of dental medicine and dental patients

“…The probability of release of TEGDMA from composite resins is high, and the risk of allergies and cytotoxicity has been recognized [29][30][31].…”

Pulpal and Periapical Response After Restoration of Deep Cavities in Dogs' Teeth With Filtek Silorane and Filtek Supreme XT Systems

“…Although these resins have better physical properties, their cytotoxicity in cell cultures has been demonstrated. 10 Filtek Supreme XT has also been shown to have a high monomer release rate 23 and cytotoxicity to L929 fibroblasts. 24 Although the characterization of tissue response is a key factor to substantiate the clinical use of new dental materials, no histopathologic study has yet evaluated pulp response in vivo after restoration of deep cavities with Filtek Supreme XT resin.…”

Composite resin vs resin cement for luting of indirect restorations: Comparison of solubility and shrinkage behavior

“…The experimental methodologies, i.e. High Performance Liquid Chromatography (HPLC), linear shrinkage and polymerization force, have been used in previous studies 8,[14][15][16][17] to detect differences within materials in respect to their response to contraction forces and to leaching of chemical components from the materials' mass.…”

“…This means that during the first hour after polymerization, the restoration has already been in contact with the humid oral environment for about 45 min. A solution of 75% ethanol/25% water was used following a published protocol 8) . This solution is recommended as a food simulator according to the guidelines of the US Food and Drug Administration 7) .…”

“…Another reason for the degradation of the cement layer has been attributed to liquid inward flow into the cement with the subsequent out-ward flow of free monomers and fillers into the oral environment 5,6) . This may result in an increased release of monomers 7,8) since in the clinical practice the luting interface is directly in contact with the oral environment shortly after polymerization. As a result, mechanical properties of the luting agent can be adversely affected, in addition to biocompatibility problems due to the release of unreacted monomers to the oral environment or, through dentin, to the dental pulp 9) .…”