Comparison of cytotoxic and apoptosis-inducing effects of MTA, propolis, and propolis-MTA on immature dental pulp stem cells.

Background: Pulpotomy is a treatment option for the preservation of pulp vitality in primary teeth with extensive caries. Propolis is a natural resinous substance with optimal antimicrobial, anti-inflammatory, and immune-regulatory properties. Thus, this study aimed to compare the cytotoxic and apoptosis-inducing effects of mineral trioxide aggregate (MTA), propolis, and MTA-propolis on immature dental pulp stem cells (IDPSCs).

Methods: In this in vitro, experimental study, primary IDPSCs were exposed to propolis, MTA, and MTA-propolis for 24 and 72-h. The cytotoxicity and apoptosis-inducing effects were evaluated using the methyl thiazolyl tetrazolium (MTT) assay and flow cytometry, respectively. Data were analyzed using ANOVA and Tukey's test at 0.05 level of significance.

Results: The cytotoxicity of MTA and MTA-propolis was higher than that of propolis alone at both 24/48 h. In addition, all tested concentrations showed higher biocompatibility at 72-h compared with 24-h (P < 0.0001). In the assessment of apoptosis, propolis-MTA showed higher cell viability compared with other materials (P < 0.0001).

Conclusion: Propolis-MTA showed higher biocompatibility than MTA. Addition of propolis to MTA improved cell proliferation in the first 24-h. Also, the cytotoxicity of propolis was lower than other materials in the first 24-h. Thus, propolis may serve as a promising pulp capping agent given that its other properties are approved.