Potential Effect of Different Pulp Capping Materials on Human Dental Pulp Stem Cells: A Laboratory Study

: Objective: This study aimed to evaluate the regenerative capacity of two different pulp capping materials TheraCal LC and Nano hydroxyapatite on stem cells extracted from the human dental pulp as a treatment modality for pulp capping. Materials and Methods: Human dental pulp stem cells were obtained and characterized. They were prepared in 12-well plates, cultured in standard culture media, and separated into three groups with 12 each. The first group served as the negative control group and contained only human dental pulp stem cells; the second group contained TheraCal LC, which was incubated with human dental pulp stem cells; and the third group contained nano-hydroxyapatite, which was incubated with human dental pulp stem cells. The 3-[4,5-dimethylthiazole-2-yl]-2,5-diphenyltetrazolium bromide (MTT) test was used to examine the cytotoxicity and proliferation of human dental pulp stem cells. Osteogenic differentiation was determined using alizarin red staining. Results: Nano-hydroxyapatite showed significantly higher cell viability at 5 days (0.281±0.03) compared to the control group (0.262±0.02) while the TheraCal LC group showed less cell viability (0.167±0.02). Nano- hydroxyapatite showed the largest calcified nodules and TheraCal LC showed the smallest. Conclusions: The application of TheraCal LC and Nano- hydroxyapatite in combination with the stem cells extracted from dental pulp tissues can be considered a suitable treatment modality for capping the pulp.