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

Abstract

This study evaluated the cytotoxicity of self-etching primers/adhesives by direct contact and dentin barrier tests. The three two-step self-etching systems Clearfil SE Bond (CSE), Clearfil Protect Bond (CPB), Prime&Bond NT/NRC (PB) and one-step self-etching systems Reactmer Bond (RB), Clearfil Tri-S Bond (CTS), and Adper Prompt L-Pop (AP) were examined. In direct contact tests, L929 cells were cultured in the presence of diluted solutions (50, 20, 10, and 1%) of primer/conditioner of adhesive systems. For dentin barrier tests, each system was applied onto 0.5 or 1.5 mm thick human dentin assembled in a simple pulp chamber device and incubated for 24 h at 37°C to make the diffusive components contact the L929 cells placed at the bottom of the chamber. The cytotoxic effects were assessed by MTT assay. Cell culture without application of any primers/adhesives served as the control for both tests. One-way ANOVA and Tukey HSD tests were used for statistical analyses. The direct contact tests demonstrated that CSE and CPB were less toxic than the other materials at all dilutions. In the dentin barrier tests, toxic effects of materials were reduced with an increase in thickness of intervening dentin. CSE and CPB showed less cytotoxicity than the other adhesives (p<0.05) when applied to 0.5 mm-thick dentin, and CSE was the least toxic in the 1.5 mm-dentin group (p<0.05). Dentin thickness positively affected biocompatibility of the tested bonding systems. Two-step self-etching systems with HEMA-based primers were more biocompatible than other self-etching adhesives.

The protective effect of resveratrol against dentin bonding agents-induced cytotoxicity

“…The structure and features of the monomers affect the cytotoxicity. In previous studies, the hydrophobic monomers Bis-GMA and UDMA have been reported to have more cytotoxic effects when compared to those of TEGDMA and HEMA 3,8,29,30) . In this study the bonding agent including UDMA (Group C) displayed the strongest cytotoxicity regarding the cell viability, while the bonding agent including HEMA (Group B) caused a lower decrease in cell viability as expected.…”

“…In the present study, the cytotoxicity of four different one-step, self-etching dentin bonding agents were analyzed with MTT assay, DCF assay, 8-OHdG measurement and comet assay in L929 mouse fibroblast cell culture model. The cytotoxicity of the resin based materials are related with dilution rate 3,27,28) . The tested dentin bonding agents had a dose-dependent (1:1>1:10>1:20) cytotoxic effect on L929 cells (Fig.…”

“…One-component and onestep dentin bonding agents have been developed for easy application with the incorporation of the new monomers 2) . As the in vitro cytotoxicity of the resin monomers is reported in the studies [2][3][4][5][6][7] , there is concern about the biological safety of these materials. Dentin bonding agents may present different cytotoxicity by the interaction of the multiple components, thus the determination of the cytotoxicity of the product instead of the monomer is significant 3,8) .…”

“…As the in vitro cytotoxicity of the resin monomers is reported in the studies [2][3][4][5][6][7] , there is concern about the biological safety of these materials. Dentin bonding agents may present different cytotoxicity by the interaction of the multiple components, thus the determination of the cytotoxicity of the product instead of the monomer is significant 3,8) . The increased reactive oxygen species (ROS) have been reported as responsible for the cytotoxic effects of the resin-based dental materials [9][10][11] .…”

The effects of restorative composite resins on the cytotoxicity of dentine bonding agents

“…Under this condition, it was evident that the cytotoxicity of the dentine bonding agent was greatly attenuated by dentine discs, suggesting that dentine provided protective effects by interfering with the free diffusion of hazardous chemicals to the target cells. Therefore, it is expected that pulp tissue is minimally damaged, if at all, by bonding agents in clinical situations due to the presence of adequate amounts of dentine 10,11) . However, there are several bonding materials that still exert cytotoxic effects on pulp cells even in the presence of a dentine barrier 12) .…”