Background and Aim: The aim of this study was to assess gutta percha-induced TNF-alpha and IL-1 beta gene expression in the presence or absence of bacterial lipo-polysaccharide (LPS) on cultured human monocyte cells in vitro.
Materials and Methods: Human monocytes from THP-1 cell line were cultured. Standardized gutta percha segments were prepared and directly placed at the bottom of the culture wells. Cultured cells were exposed to the materials in G1 and G2 groups and then LPS was added only to G1. Positive control included the bacterial LPS without the gutta percha segments and the negative control contained the cells in culture medium only. TNF-alpha and IL1-beta gene expression was evaluated using RT-PCR technique. Data were statistically analyzed using Kruskal-Wallis and Bonferroni-adjusted post-hoc tests.
Results: A statistically significant difference was noted between LPS-treated and un-treated groups regarding IL-1-beta and TNF-alpha gene expression (p < 0.05). In G2 (the gutta-percha without LPS), IL-1-beta, and TNF-alpha gene expression was signifi-cantly higher compared to the negative control group (p < 0.05). In G1 (gutta-percha with LPS), TNF-alpha and IL-1-beta gene expression was significantly higher than in the positive control group (p<0.05).
Conclusion: It was indicated that gutta-percha could induce the expression of pro-inflammatory cytokines TNF-alpha and IL-1-beta, with this effect being significantly magnified by LPS contamination.