Mode of cell death of co-cultured dental mesenchymal stem cells following exposure to endodontic irrigating solutions

Aims: This in vitro study aimed to determine the mode of cell death of co-cultured dental mesenchymal stem cells following exposure to different irrigating solutions.Methods and Material: Mesenchymal stem cells of the apical papilla (SCAPs) and periodontal ligament stem cells (PDLSCs) were isolated from the periapical region of a third molar of an 18-year-old patient and cultured. Adequate number of cells in each well, 6-well plate inserts were placed over the wells. The cells were then randomly exposed to 17% ethylenediaminetetraacetic acid (EDTA), 1.5% sodium hypochlorite (NaOCL), 2% chlorhexidine (CHX) and saline. After 1, 5, and 10 minutes cells were trypsinized and underwent flow cytometry. Apoptotic and necrotic cells were quantified. Data were analyzed using the One-way ANOVA and Tukey’s post-hoc test. Results: With increasing exposure time, cell viability is decrease and the mode of cells death was necrosis in CHX and NaOCL groups and necrosis plus late apoptosis in 1 and 10 minutes in EDTA group.Conclusion: Maximum cell death occurred following exposure to EDTA while minimum cell death occurred following exposure to CHX. Necrosis was the dominant mode of cell death in all groups.