Objectives

to assess the cytotoxicity of the following functional monomers used in dental adhesives: 10-Methacryloyloxydecyl dihydrogen phosphate (10-MDP) and glycerol phosphate dimethacrylate (GPDM), and their effect on cytokine release from human dental pulp stem cells (hDPSCs).

Methods

The hDPSCs cells were isolated from the dental pulp of extracted human third molars. The functional monomers, 10-MDP and GPDM, were diluted in dimethyl sulfoxide (DMSO) at concentrations ranging from 1 to 4 mM. Cells not exposed to the compounds served as controls. The hDPSCs were seeded into 96-well plates and incubated for 48 h. Subsequently, the cells were exposed to 10-MDP and GPDM for 24 h. Then, the culture medium was removed, the mitochondrial metabolism was evaluated using the MTT assay, while cell death analyzed by flow cytometry. Cytokine release (IL-1β, IL-6, IL-8, IL-10, TNF-α) was analyzed by the MAGPIX. The data were analyzed using one-way ANOVA and Tukey's test.

Results

10-MDP demonstrated significant toxicity to hDPSCs, reaching the IC50 at 3 mM. However, its impact on cytokine release was minimal, resulting only in IL-6 and IL-8 levels. GPDM exhibited lower toxicity, even at 4 mM, but induced an increase in IL-1β release and a reduction in IL-6, IL-8, and IL-10 levels, with no effect on TNF-α. Despite the MTT assay results indicating cytotoxicity, the cell death was low for both functional monomers.

Significance

10-MDP exhibited significant toxicity to hDPSCs, unlike GPDM, however, both monomers resulted in minimal cell death. 10-MDP had a minor impact on cytokine release, whereas GPDM demonstrated a potential to trigger an inflammatory reaction, particularly in the short term.