Evaluation of Cytotoxicity of Premixed Triple Antibiotic Paste on Stem Cells of Apical Papilla Using MTT Assay: An In Vitro Study.

Background: Endodontic regenerative procedures are biologically based and intend to replace damaged dental tissues. This includes the restoration of the dentin-pulp complex through the use of stem cells. Root canal medications, particularly antibiotics, have shown significance in obtaining excellent therapeutic outcomes. However, high concentrations of some materials, like calcium hydroxide [Ca(OH)2] and mineral trioxide aggregate (MTA), can be cytotoxic, which necessitates a search for less toxic alternatives. Aim: To evaluate the cytotoxic effects of premixed triple antibiotic paste (TAP) on stem cells of apical papilla (SCAPs) using methyl thiazolyl tetrazolium (MTT) assay. Materials and methods: Stem cells of apical papilla were isolated from the dental pulp tissue of extracted premolars and characterized using flow cytometry. The isolated cells were divided into four groups: Groups I, II, and III were treated with TAP at concentrations of 10, 25, and 50 μg/mL, respectively, while group IV served as the untreated control. The MTT assay was performed according to the manufacturer's protocol to assess cell viability. Evaluations were carried out at 1, 3, and 7 days following exposure to the TAP concentrations. Results: Cell viability was highest in groups treated with 10 and 25 μg/mL TAP, indicating minimal cytotoxicity across all evaluated time points-1, 3, and 7 days. In contrast, the group exposed to 50 μg/mL TAP demonstrated significantly reduced cell viability, indicating a dose-dependent increase in cytotoxicity. Conclusion: This study concludes that TAP at concentrations of 10 and 25 μg/mL demonstrates higher cell viability and lower cytotoxicity on SCAPs across 1, 3, and 7 days of evaluation. In contrast, a concentration of 50 μg/mL exhibited the most pronounced cytotoxic effects. While these findings suggest that lower concentrations of TAP may be safer for regenerative applications, further in vivo studies and preclinical animal trials are warranted to confirm biocompatibility and clinical feasibility prior to translation into human use. How to cite this article: Saravanan E, Ravindran V. Evaluation of Cytotoxicity of Premixed Triple Antibiotic Paste on Stem Cells of Apical Papilla Using MTT Assay: An In Vitro Study. Int J Clin Pediatr Dent 2025;18(9):1082-1086.