Development and Evaluation of the Physico-Chemical and Biological Properties of New Experimental Hydraulic Silicates

To evaluate the physico-chemical and biological properties of experimental hydraulic cements (EHCs) prepared after the synthesis of tricalcium silicate (C₃S), calcium zirconium silicate (CZS), and strontium phosphate silicate (SPS) in comparison with Biodentine (BD). After synthesizing and characterizing the silicates (FTIR/XRD/SEM-EDS/TEM), EHCs were analyzed for setting, radiopacity, dimensional stability, compressive strength, solubility, pH, calcium/strontium ion release, and biocompatibility. Significant differences were observed in setting times, with BD3S/CZS and BD/SPS3S, both in initial and final (p < 0.05); BD offered shorter times. Regarding radiopacity, the materials ranked as SPS>CZS>C₃S>BD (p < 0.05). No differences were observed in dimensional stability (24 h/30 days) (p > 0.05). BD showed higher compressive strength than EHCs in both assessed periods (p < 0.05); EHCs exhibited an increase over time (p < 0.05). Regarding solubility, BD had less mass loss in both periods (p < 0.05). Regarding pH, differences were found at 3 h/15 days between BD (8.70; 7.99) and C₃S/CZS cements (p < 0.05). At 72 h/168 h, C₃S (9.50; 9.23) showed higher values than SPS/BD and CZS/BD, respectively (p < 0.05). For calcium/strontium release, differences were observed at 3 h between C₃S/CZS/BD and SPS (p < 0.05). In subsequent periods, SPS provided the highest release, superior to C₃S/CZS (p < 0.05). Regarding biocompatibility, no significant differences were observed in the presence of polymorphonuclear cells, mononuclear cells, or fibroblasts (p > 0.05); less vascularization was observed at 30 days for BD/C₃S/CZS (p < 0.05). Under the study's conditions, it can be concluded that EHCs exhibited promising physicochemical properties, which can still be improved, and adequate biocompatibility. Thus, this article highlights the possibility of developing new silicate-based hydraulic cements.