Objective: To investigate the preventive effect of silver diamine fluoride (SDF) modified salivary pellicle (SP) against dental erosion.
Methods: Enamel and dentin blocks allocated into 4 groups (n = 30 each). Blocks in Group SDF+SP were treated with SDF and SP. Blocks in Group SDF were treated with SDF. Blocks in Group DW+SP were treated with deionized water (DW) and SP. Blocks in Group DW were treated with DW. The blocks were subjected to an erosive challenge at pH 3.2 for 2 mins, 5 times per day for 14 days. Salivary pellicle morphology was assessed by atomic force microscopy (AFM). Crystal characteristics, percentage microhardness loss (%SMHL), surface loss, and surface morphology were assessed by X-ray diffraction (XRD), microhardness test, profilometry, and scanning electron microscopy (SEM), respectively.
Results: AFM revealed a modified pellicle morphology in Group SDF+SP. XRD of both blocks revealed hydroxyapatite, silver chloride, silver phosphate, and silver fluoride in Groups SDF+SP and SDF. Fluoroapatite was found in Group SDF+SP only. %SMHL ( ± Standard deviation in %) of Groups SDF+SP, SDF, DW+SP, and DW were 33.4 ± 2.2, 38.6 ± 2.2, 50.3 ± 2.2, and 58.3 ± 2.4 in enamel and 16.1 ± 2.2, 19.7 ± 2.1, 32.8 ± 2.1, and 39.0 ± 2.3 in dentin, respectively. The presence of SDF and SP reduced %SMHL in both blocks (p < 0.001). The surface loss ( ± Standard deviation in μm) of Groups SDF+SP, SDF, DW+SP, and DW were 3.6 ± 0.7, 4.1 ± 0.4, 5.3 ± 0.5, and 7.0 ± 0.6 in enamel and 5.4 ± 0.6, 6.1 ± 0.5, 9.1 ± 0.7, and 9.2 ± 0.5 in dentin, respectively. The presence of SDF and SP reduced surface loss in enamel and dentin blocks (p = 0.031 and p = 0.002, respectively). SEM showed enamel surface remained relatively smooth and partially dentinal tubule occlusion on dentin blocks in Groups SDF+SP and SDF.
Conclusion: SDF had a positively synergistic effect with SP. SDF-modified salivary pellicle provided a superior protective effect against dental erosion.
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.