Antibacterial activity of a plant extract and its potential for disinfecting gutta-percha cones

This study evaluated the antibacterial activity of Rosmarinus officinalis extract and its potential for disinfecting guttapercha (GP) cones. In the first experiment, a hydro-alcoholic extract of Rosmarinus officinalis (leaves) in a dilution ratio of 10% m/v was tested against Enterococcus faecalis by using the disk diffusion method. Positive and negative controls were 70% cereal alcohol and antibiotics, respectively. The procedures were performed in triplicate, and the diameters of the zones of growth inhibition were measured with a caliper after 24 h at 37 degrees C. In the second experiment, the disinfection procedures were evaluated on GP cones artificially contaminated with Enterococcus faecalis. The R. officinalis extract was compared with 2% chlorhexidine digluconate and 2.5% sodium hypochlorite, using a direct exposure test (5 min treatment). Sterilized and non-disinfected cones were used as negative and positive controls, respectively. After 24 h of incubation, bacterial counts were taken. For both experiments, the data were statistically analyzed by Kruskall-Wallis and Tukey's tests (p < 0.05). The plant extract produced zones of inhibition comparable to those of tested antibiotics. Significant GP cone disinfection was verified with all disinfectant solutions, with no significant difference between them. R. officinalis extract showed bactericidal effect on Enterococcus faecalis and capacity to disinfect GP cones contamined with it.