Assessment of fluoride-infused calcium phosphate resin composites as effective remineralisation agents for human dental pulp stem cells

Objectives: This study aimed at developing specific experimental pulp-protection resin-based materials containing bioactive FDCP fillers and assessing their influence on essential functions of human Dental Pulp Stem Cells (hDPSCs), including cytotoxicity, stemness, and cell migration, as well as their activation of mineralisation processes. Methods: Experimental FDCPCs were synthesized incorporating varying concentrations of calcium and sodium fluoride salts (5, 10 and 20 wt%). A free FDCP filler (R-VS0F) served as the control group. The hDPSCs were exposed to eluates from these materials to assess cytocompatibility, self-renewal capacity and migratory behavior. The osteogenic differentiation potential was evaluated via Alkaline Phosphatase (ALP) activity and Alizarin Red S staining (ARS). Furthermore, the gene expression analysis assessed the expression levels of key osteogenic and odontogenic markers, including OCN, OPN, COL1α1, DSPP, MEPE, and DMP-1. Results: All tested FDCP fillers exhibited significant cytotoxicity at undiluted concentrations (1:1 dilution) under basal and osteogenic conditions, while no adverse effects on cell viability were observed at higher dilutions. The materials did not affect hDPSC migration; however, the R-VS20F formulation notably enhanced self-renewal capacity compared to other tested concentrations. FDCP fillers modulated early osteogenic activity, as indicated by increased ALP activity. Mineralization was not significantly influenced by any of the FDCP fillers. Notably, an upregulation of odontogenic gene markers—MEPE, DSPP, and DMP1—was observed, particularly in hDPSCs treated with R-VS0F. Significance: This study highlights the potential of FDCP-based resin materials to modulate dental pulp stem cell behaviour in a concentration-dependent manner. Optimizing ion release profiles can enhance regenerative outcomes in vital pulp therapy, supporting the development of bioactive materials that may actively promote dentin–pulp complex repair.