Role of magnesium on phase composition of tricalcium phosphate and its interaction with human dental pulp stem cells

Tricalcium phosphates (TCPs) are of great interest in dental tissue engineering applications. The objective of this study was to incorporate magnesium (Mg) at different concentrations of 0.25, 0.50, 1.00, 2.50, and 5.00 wt.% to TCP and evaluate the effects on phase composition, density, and in vitro interaction with human dental pulp stem cells (hDPSCs). Our results showed that adding Mg stabilized the β-TCP crystal structure and increased the density of the TCP. Mg addition had no adverse effect on hPDSCs response. Although cellular proliferation was slightly less on Mg-TCPs at early time points, it increased significantly with time and in a dose-dependent manner. A similar trend was observed for cellular differentiation. Together, these data show for the first time that Mg addition at concentrations less than 2.50% (preferably at 1.00 or 2.50 wt.%) can be added safely to TCP for enhanced proliferation and differentiation of hDPSCs. Graphical abstract