Assessing Cell Viability: Comparative Analysis of Calcium Hydroxide, Triple Antibiotic Paste, and Their Synergistic Impact on human Dental Pulp Stem Cells

Objective The American Association of Endodontists recommends the use of calcium hydroxide (Ca(OH)2) or triple antibiotic paste (TAP) as preferred medicaments in regenerative endodontic treatment. Although both medicaments showed an excellent antibacterial property, their impact on the viability of human dental pulp stem cells (hDPSCs) when used in combination remains uncertain. Previous studies have indicated that at certain concentrations, both Ca(OH)2 and TAP can be harmful to cells. Therefore, it is aimed to assess the effects of Ca(OH)2, TAP, and their combined application on the viability of hDPSCs in this study. Materials and Methods Primary cultured hDPSCs, reaching 80% confluency and at passages 3rd to 4th, were subjected to 24-hour starvation. Subsequently, they were cultured in media supplemented with Ca(OH)2, TAP at 0.1 and 1 mg/mL concentrations, and a combination of Ca(OH)2 and TAP at equivalent concentrations, with Dulbecco's modified eagle medium serving as the control group. The viability and morphology of hDPSCs were assessed using both the quantitative 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay and qualitative 4',6-diamidino-2-phenylindole staining. Statistical Analysis First, the data were analyzed by one-way analysis of variance, followed by Bonferroni post hoc to compare between groups. All the tests were conducted at a significance level of 95% (p < 0.05). Results In this study, a notable variation in hDPSCs viability was observed among all groups, with the lowest viability recorded in the combination of Ca(OH)2 + TAP at 1 mg/mL (p < 0.05). Conclusion Ca(OH)2, TAP, and their combination are not toxic to hDPSCs and the use of their combination was superior in hDPSCs viability on Ca(OH)2 + TAP in the 0.1 mg/mL group.