Badr AE, Omar N, Badria FA A laboratory evaluation of the antibacterial and cytotoxic effect of Liquorice when used as root canal medicament. International Endodontic Journal, 44, 51–58, 2011.
Aim To evaluate the antibacterial and cytotoxic effects of Liquorice as a root canal medicament and to compare its action to the commonly used root canal medicament calcium hydroxide Ca(OH)2.
Methodology The antibacterial effect of Liquorice and Ca(OH)2 either separately or in combination was investigated against Enterococcus faecalis. Agar-well diffusion methods, broth microdilution tests and biofilm susceptibility assays were used to determine the antibacterial activity. Human periodontal ligament fibroblast tissue culture was used to assess the cytotoxicity of the preparations under investigation.
Results Liquorice extract either by itself or in combination with Ca(OH)2 had a significant inhibitory effect against Enterococcus faecalis compared with that of Ca(OH)2 alone. The use of Liquorice extract followed by Liquorice/Ca(OH)2 mixture retained significantly more viable periodontal ligament cells than Ca(OH)2, which had a strong lethal effect on the cells.
Conclusion Liquorice extract either separately or as Liquorice/Ca(OH)2 mixture had a potent bactericidal effect against Enterococcus faecalis and retained compatibility with fibroblasts in tissue culture compared to the commonly used root canal medicament Ca(OH)2.