Effects of Bioactive Pulp-capping Materials on Cell Viability, Differentiation, and Mineralization Behaviors of Human Dental Pulp Stem Cells In Vitro

Purpose: The objective of this study was to assess the effect of bioactive pulp-capping materials on human dental pulp stem cell (hDPSC) behavior in terms of cell viability and bioactivity via mineralization potential. Methods and Materials: Nanoparticles of 58S5 bioactive glass (nBG) powder were elaborated by a sol-gel process. Primer hDPSCs were cultured with experimental nBG, Biodentine, TheraCal LC, and ProRoot mineral trioxide aggregate (MTA) extracts. Cell viability was measured for 1, 3, and 7 days by water-soluble tetrazolium salts (WST-1) assay. Expression of mineralization-related marker genes (dentin sialophosphoprotein [DSPP] and osteocalcin [OCN]) was quantified by a real-time polymerase chain reaction. Detection of DSPP protein expression in hDPSCs was also assessed by western blotting. Alizarin red staining was used to detect the formation of mineralized nodules, and alkaline phosphatase (ALP) activity was quantified by a photometric method (days 7 and 14). All data were statistically analyzed with a one-way analysis of variance (ANOVA) and Tukey's post-hoc test (p<0.05). Results: The cell viability of hDPSCs in all groups decreased except for nBG, and the lowest cell viability was determined in TheraCal LC at all incubation times. nBG and MTA showed significantly higher ALP activity than the control group. The tested materials elevated the calcium nodule form of hDPSCs except for TheraCal LC. The highest DSPP expression was seen in nBG for both incubation times. Conclusion: nBG promotes differentiation and mineralization of hDPSCs at a higher rate than other bioactive pulp-capping materials tested.