In Vitro Evaluation of Novel Calcium Silicate-Based and Resin-Modified Calcium Silicate Materials: Cytocompatibility and Mineralization Potential on Human Dental Pulp Stem Cells for Pulp Repair

Abstract

This study aimed to evaluate the biological effects of three calcium silicate-based materials-Biodentine XP (BD-XP), TheraCal PT (THPT), and TheraBase Ca (THB)-on human dental pulp stem cells (hDPSCs), focusing on cytocompatibility, immunomodulatory behavior (via IL-6 expression), and odontogenic/mineralization potential compared to control conditions. hDPSCs were cultured with eluates (25%, 50%, 100%) of BD-XP, THPT, and THB. Cytocompatibility was assessed via metabolic activity assay, cell cycle analysis, and cell migration. Morphology and adhesion were examined by SEM, while surface composition was analyzed by EDX. IL-6 secretion was quantified using ELISA. Gene expression of odontogenic/osteogenic markers (ALP, DSPP, RUNX2, COL-1) was analyzed via qRT-PCR at 14 and 21 days. Alizarin Red S staining was used to assess mineralization. Results were compared to unconditioned and osteogenic controls (p < 0.05). All materials exhibited acceptable cytocompatibility. BD-XP promoted the highest cell viability, migration, and adhesion. IL-6 secretion was significantly reduced in all treated groups, most notably with THB. SEM and EDX showed strong cell attachment and calcium-rich surfaces for BD-XP. BD-XP significantly upregulated DSPP and RUNX2 at both time points and COL-1 at day 21. ALP expression was mainly observed in the positive control. BD-XP also showed the greatest mineralized nodule formation. Biodentine XP demonstrated the most favorable biological behavior, showing high cytocompatibility, upregulation of odontogenic markers, and enhanced mineralization. These results highlight its potential for clinical use in vital pulp therapy and regenerative endodontics.