IN VITRO ANTIBACTERIAL ACTIVITY OF PHYTOCHEMICALS ON DENTAL BIOFILM MICROORGANISMS

Abstract

Objective: To evaluate the in vitro antibacterial activity of citronellol, linalool, thymol, and D-limonene against Streptococcus mutans, S. salivarius and S. oralis. Material and Methods: It was performed a screening by the diffusion technique on solid medium. Absorbent paper discs were soaked with 30 µl of the tested substance and then placed on petri dishes containing Mueller Hinton agar previously sown with the bacterial inoculum. After incubation for 24 h at 37 °C, it was measured the halo of growth inhibition with the aid of a manual caliper. Chlorhexidine (2%) was used as positive control. Tests were performed in triplicate. Results: For citronellol, the means of the diameters of the halos, in millimeters (mm), were 10.7, 10.0, and 9.8 against S. mutans, S. salivarius and S. oralis respectively. The values found for thymol were 7.3, 7.3 and 8.3 mm, respectively. The phytochemical D-limonene exhibited means of 8.0, 6.7 and 6.0 mm, respectively. For linalool, the means of the halos were 8.0 mm, 9.0 mm and 8.2 mm. Chlorhexidine was found to show means of 17, 16.8 and 19.7 mm on S. mutans, S. oralis and S. salivarius respectively. Conclusion: The products under test showed antibacterial activity, being therefore potential substances to be applied for dental caries prevention. DESCRIPTORS: Biological Agents. Streptococcus mutans. Streptococcus oralis.