Biocompatibility and osteogenic assessment of experimental fluoride-doped calcium-phosphate cements on human dental pulp stem cells

Abstract

Objectives: This study investigated the impact of some specific experimental calcium phosphate cements doped with different fluoride salts (FDCPCs) concentrations on the basal functions of human Dental Pulp Stem Cells (hDPSCs). Furthermore, this study also examined the migration, as well as the mineralisation through osteogenic differentiation.

Methods: Experimental FDCPCs were formulated using different concentrations of calcium/sodium fluoride salts [(5 wt%: VS5F), (10 wt%: VS10F), (20 wt%: VS20F)]. A fluoride-free calcium phosphate (VS0F) was used as a control. The hDPSCs were assessed to evaluate their self-renewal and migration activity in the presence of eluates of the different FDCPCs. A viability assay in osteogenic conditions was carried out, along with the differentiation potential through Alkaline Phosphatase Activity (ALP), and Alizarin Red Staining (ARS). Moreover, the gene expression of specific markers (RUNX2, ALP, COL1α1, OCN, OPN, DSPP, MEPE, and DMP-1) was also evaluated.

Results: All the tested FDCPD had no influence on cell migrations, but they caused a decrease in cell viability in osteogenic conditions when not diluted. Conversely, the eluants of VS20F showed a positive effect on stem cell differentiation. This result was corroborated through ALP activity, ARS assay. Moreover, upregulation of specific gene markers such as RUNX2, DMP-1, and DSPP was observed in hDPSCs, especially when treated with VS20F.

Significance: The experimental FDCPC tested in this study exhibits a dose-dependent capacity to promote mineralisation in osteogenic environment. The FDCPC-VS20F seems to be the most promising experimental material suitable for developing of pulp-capping materials with osteogenic and bioactive properties.

Keywords: Biocompatibility; Calcium phosphate; Human dental pulp stem cells; Ion-release; Osteogenic; Remineralisation markers.