Comparison of Cytotoxicity between Mineral Trioxide Aggregate Mixed with Chlorhexidine and Common Endodontic Regeneration Medicaments on Periodontal Ligament Stem Cells: an in Vitro Study.

Objectives: The combination of mineral trioxide aggregate (MTA) and 2% chlorhexidine (CHX) has been recently introduced as an intracanal medicament. The aim of this study was to evaluate the potential cytotoxic effects of MTA mixed with 2% chlorhexidine gel on human periodontal ligament stem cells (PDLSCs) and compare it with other common endodontic regeneration medicaments. Materials and Methods: Minimum inhibitory concentration and minimum bactericidal concentration of six experimental groups against Enterococcus faecalis was determined. The study groups consisted of RetoMTA mixed with 2% chlorhexidine gel (MTA+CHX), calcium hydroxide (CH), CH mixed with CHX gel, two concentrations of double antibiotic paste, and 2% CHX. The direct cytotoxic effect of minimum bactericidal concentration was evaluated by MTT on PDLSCs on days 1, 3, and 7. One-way ANOVA and post hoc tests were used for data analysis (P<0.05). Results: The viability of cells treated with MTA+CHX decreased significantly over time (P<0.05) making this group the most cytotoxic intracanal medicament on the 3^rd and 7^th days of treatment. On day one, the highest viability percentage was detected in the CH+CHX group followed by the CHX group. On day 3, CH+CHX and CHX groups displayed the highest viability percentage. On day 7, the highest viability was observed in the CHX group, which showed no significant difference with the control group (P=0.12). Conclusion: Regarding the antimicrobial potency of intracanal medicaments at minimum bactericidal concentration levels, CHX gel appears to be the least cytotoxic drug, while MTA+CHX shows the highest reduction in viability percentage.