Abstract: Objective: To explore the effect of Mg²⁺ on hPDLCs osteogenic differentiation capability, and to determine the appropriate concentration range of Mg²⁺ to provide the basis for choosing Mg²⁺ infuse concentration in future periodontal regeneration research. Methods: hPDLCs stimulated with the presence of Mg²⁺ at various concentrations (from 0 to 50 mmol/L) were cultured in control medium and osteogenic medium, respectively. CCK8 was used to estimate the cell proliferation level, ALP activity assays were performed to detect the ALP activity differences in each group and alizarin red staining was used to determine the calcium mineral density. The mRNA expression levels of Runx2, ALP, Col1, OPN, and Bglap in hPDLCs with Mg²⁺ at concentrations of 0 and 15 mmol/L were examined by RT-qPCR of post-osteogenic induction. The results were analyzed using analysis of variance (ANOVA) and Student-Newman-Keuls (SNK) test for pairwise comparisons implemented in the SPSS 16.0 software. Results: Mg²⁺ at concentrations of 10, 15, and 25 mmol/L promoted hPDLCs proliferation and ALP activity, whereas Mg²⁺ at concentrations of 35 and 50 mmol/L remarkably inhibit hPDLCs proliferation and ALP activity. Conclusion: Proper Mg²⁺ concentration (0-25mmol/L) can promote early-term osteogenic differentiation of hPDLCs and inhibit mineralization.

Key words: Periodontal ligament cells, Magnesium ion , Cell proliferation , Osteogenic differentiation, Osteopontin