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Background: Since the introduction of amalgam for tooth fillings, there have been concerns that mercury toxicity could pose unacceptable health risks. Rasa shastra is an ancient medical discipline that focuses on the utilization of metals and minerals for the treatment of diseases. Nevertheless, these minerals cannot be directly administered to the human body in their natural state due to their potential adverse effects. Hence, for medicinal purposes, these metals and minerals need to undergo purification (Shodhana) to eliminate impurities and modify their physical, chemical, and biological characteristics. Methodology: Human gingival fibroblasts (HGF) were exposed to commercially available mercury (CA-Hg) and ayurvedically purified mercury (AP-Hg) at concentrations of 6.25 µM, 12.5 µM, 25 µM and 50 µM. The unexposed HGF cultured in basal media was considered a control. All the samples were cultured for 24 hours and 48 hours, and the cytotoxicity was analyzed by MTT assay. Results: Cell viability between the control and experimental groups varied at 24 hours, however, the results were not statistically significant (p>0.05). At 48 hours, cell viability was higher in the AP-Hg group as compared to the CA-Hg group at the concentration of 6.25 µM, and the difference was statistically significant (p<0.05). The cell proliferation assay results demonstrated a statistically significant difference in the mean optical density values (p<0.05) between CA-Hg and AP-Hg at 12.50 µM, 25 µM, and 50, µM concentrations observed at 24 hours. At 48 hours, a statistically significant difference in the mean OD values (p<0.05) between CA-Hg and AP-Hg at all four concentrations was observed. Conclusion: AP-Hg at a concentration of 6.25 µM demonstrated higher cell viability at 48 hours. Further, the cell proliferation rate was also higher for AP-Hg at all concentrations at 24 and 48 hours. These results indicated a less cytotoxic effect of AP-Hg than CA-Hg in HGF and hence could be employed for dental amalgam preparations.
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Stem cells from human exfoliated deciduous teeth (SHED) provide an important autologous source for stem cell-based regenerative therapies with their easy acquisition and multipotency. However, the understanding of their antibacterial and immunomodulatory properties is limited. This in vitro research aims to determine whether SHED inhibits the growth of Streptococcus mutans (S. mutans) and Enterococcus faecalis (E. faecalis), as well as whether or not it has immunomodulatory effects by measuring interleukins (ILs)-2 and -6 levels. SHEDs were derived from the pulp of deciduous teeth that had undergone up to two-thirds of their roots' resorption. Isolated SHEDs were characterized on their morphological features, viability, assessment of surface markers, and in vitro induction into osteocytes and adipocytes. SHED was tested for its antibacterial efficacy against S. mutans and E. faecalis using a colony-forming units (CFU) assay. Lastly, we checked the cytokine levels by enzyme-linked immune sorbent assay (ELISA) for assessing the immunomodulatory properties of SHED. The results showed that the established SHED had fibroblastic morphology with higher viability. The ability to differentiate into osteocytes and adipocytes, as well as the expression of stem cell-specific markers, demonstrated their potential and flexibility under in vitro settings. SHED demonstrated antibacterial characteristics by significantly (p < 0.05) lowering S. mutans CFU, whereas E. faecalis CFU was either unaffected by or just slightly affected by the cells. SHED also helped keep inflammatory indicators, including IL-2 and IL-6, at stable levels when compared to the control. The results indicate that SHED may aid in preventing or reducing an infection due to its antibacterial activity and may provide immunomodulatory activities by controlling the production of cytokines. How to cite this article: Tyagi A, Shetty J, Shetty S, et al. Antibacterial and Immunomodulatory Properties of Stem Cells from Human Exfoliated Deciduous Teeth: An In Vitro Study. Int J Clin Pediatr Dent 2023;16(S-3):S240-S246.
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OBJECTIVES: Periodontal ligament-derived stem cells (PDLSCs) are regarded as a viable option for periodontal regeneration using cell sheet technology. The objective of the present in vitro study was to characterize human PDLSCs based on their phenotypic and biological properties and to evaluate the ascorbic acid (AA or vitamin C)-induced cell sheet by analyzing the molecular markers. METHODS: PDLSCs were established from premolars, and their morphology, viability, proliferation, phenotypic marker expression, and ability to differentiate into osteocytes and adipocytes were analyzed. PDLSCs were then induced to form cell sheets using 100 µM AA, and gene expression was examined by real-time polymerase chain reaction. RESULTS: PDLSCs showed fibroblastic morphology with >95% viability. The cells were highly proliferative and positive for surface antigens CD29, CD73, and CD90 but negative for CD34 and CD45. They were capable of differentiating into osteocytes and adipocytes. Induction with 100 µM AA transformed PDLSCs into two-to three-layered cell sheets. There was no significant upregulation in ALP and RUNX2 expression in the AA-induced cell sheet. However, the expression levels of late osteoblast differentiation marker (bone gamma-carboxy glutamate protein); cementogenic markers (cementum attachment protein and CP23), and genes encoding extracellular matrix (ECM) proteins [collagen type 1 alpha 1 and integrin beta 1) were higher in AA-induced cell sheets by PDLSCs. CONCLUSIONS: The stimulating effect of AA on cell sheet formation by PDLSCs was confirmed by the expression of typical markers involved in osteogenesis/cementogenesis and ECM secretion, which makes this procedure a prospective option for periodontal tissue regeneration applications.