The effects of surface pre-reacted glass-ionomer (S-PRG) filler on pulpal cells and on the composition of dentinal deposits were investigated. Proliferation (CCK-8), cytotoxicity (LDH), and differentiation activity (ALP) tests, along with cell morphology observations, were conducted at 6 and 24 h after treatment of pulpal cells with different S-PRG filler eluate concentrations. Dentinal surfaces were immersed in deionized water or S-PRG filler eluate followed by immersion in deionized water or simulated body fluid and observed under scanning electron microscope and elemental analysis using energy dispersive x-ray spectrometer. At 24 h, there were significant differences in CCK-8 and ALP activity values between the groups in a concentrationdependent manner. LDH test data were not significantly different among the groups.Cell morphology was not altered at either exposure time. However, decreased cellular density was observed with the highest eluate concentration. Crystalline deposits and occluded dentinal tubules were observed in samples immersed in S-PRG filler with a later immersion in simulated body fluid, which also showed higher concentrations of certain ions compared to surfaces that were not initially treated with S-PRG filler. The lowest two eluate concentrations did not show significant toxicity. S-PRG enhanced the effect of simulated body fluid in the formation of mineral deposits.
Objectives Despite the agreement that there is no longer any indication for arsenic use in modern endodontics, some concerns are surfacing about the minute amount of arsenic trioxide (As2O3) released from Portland cement-based materials. The present study investigated the effect of different concentrations of As2O3 on rat pulpal cells and the efficacy of N-acetylcysteine (NAC) in preventing As2O3-mediated toxicity. Materials and Methods Cytotoxicities of 50, 10, or 5 µm As2O3 and the effect of cells co-treatment with 50 µm As2O3 and 5,000 µm NAC or 500 µm NAC were tested at 24 hours or 3 days. Cell viability was assessed by means of MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay and cellular morphological changes were observed under phase contrast microscope. Statistical Analysis Two-way analysis of variance with Tukey’s post-hoc test was used to evaluate differences between the groups (α = 0.05). Results At both exposure times, 50 µm As2O3 resulted in lower optical density (OD) values when compared with 10 or 5 µm As2O3. At 24 hours, 10 µm As2O3 resulted in a higher OD value compared with the control; however, at 3 days the difference was statistically insignificant. At each exposure time, the OD value of 5 µm As2O3 group was comparable to the control and 10 µm As2O3 group. There were no significant differences between 50 µm As2O3 group and 500 NAC+50 µm As2O3 group; however, these two groups had lower OD values when compared with 5,000 NAC + 50 µm As2O3 group at 24 hours and 3 days. The latter group showed significantly lower OD value in comparison with the control at 24 hours and 3 days. Control cells were polygonal-shaped while 50 µm As2O3-treated cells exhibited contracted and spherical morphology with increased intercellular spaces. At 24 hours, 10 μm and 5 µm As2O3-treated cells were slightly hypertrophic. Cells co-treated with NAC and As2O3 showed increased intercellular spaces and lower cellular density compared with the control. Conclusions As2O3 displayed a hormetic effect on pulpal cells; however, the proliferative effect induced by low As2O3 concentrations should be interpreted with caution. NAC did not prevent As2O3-mediated toxicity; however, it demonstrated potential for ameliorating this toxicity.
Objective: Despite the controversial results regarding the amount of arsenic (As) in mineral trioxide aggregate (MTA) and MTA-like cements, it is prudent to assess the effect of this heavy metal on pulpal cells and search for methods to attenuate its toxicity. This study investigated the toxic effect of As on pulpal-like cells and evaluated the influence of reduced glutathione (GSH) on As-induced toxicity. Methods: The cytotoxicity of 50 µm As, 50 µm As+50 µM GSH, 50µm As+500 µM GSH or 50 µm As+5000 µM GSH on rat pulpal cells (RPC-C2A) was evaluated at 24 hours and 72 hours. Cell culture in fresh medium without experimental solution served as the control. Cell viability was measured by means of 3-(4.5-dimethylthiazol-2-yl)-2.5-diphenyltetrazolium bromide (MTT) assay and the optical density was measured with microplate reader. The morphology of the cultured cells was observed under phase contrast microscope. Cytotoxicity data were analyzed by two-way ANOVA and Tukey post hoc tests (P<0.05). Results: There were statistically significant differences in cell viability amongst the tested groups (P<0.05). As elicited remarkable toxic effect on pulpal cells, while 5000 µM GSH protected the cells from As-induced damage at 24-hour exposure time. The cultured control cells were polygonal-shaped; however, As-treated cells exhibited contracted and spherical morphology with increased intercellular spaces indicative of cellular death and decreased proliferation. Conclusion: As negatively affected the viability of pulpal cells; however, controlled concentration of GSH had a short-term protective effect against As-induced toxicity. Future research is warranted on the clinical use of GSH with MTA and MTA-like cements to minimize initial inflammation resulting from As release during the setting of the aforementioned cements thus enhancing the success of procedures where these cements are placed in direct contact with vital pulp tissues.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.