Antibacterial activity of a phytotherapeutic (Arctium lappa) for intra-canal use

The discovery of natural biocomponents from plants with effective antibacterial activity on endodontic microbiota can lead to new therapies in Dentistry. Objectives: The present study evaluated the antibacterial activity of a phytotherapic agent prepared from a ethyl acetate fraction (AcOEt) originating from Arctium lappa. This was compared to calcium hydroxide as an intracanal dressing. Methods: Twenty-seven maxillary canines were instrumented, sterilized, and then contaminated with a mixed bacterial suspension of: Pseudomonas aeruginosa, Escherichia coli, Lactobacillus acidophilus, Streptococcus mutans and Candida albicans. The teeth were divided into 3 groups: group I: root canals were filled with calcium hydroxide and propylene glycol; group II: root canals were filled with a paste containing AcOEt fraction of A. lappa and propylene glycol; group III: root canals were filled with only propylene glycol (control). At intervals of 7, 14 and 30 days, three teeth from each group were opened and a paper point was placed in the root canal for 5 min. After collection, the points were transferred to Petri dishes with BHI and the bacterial growth was classified as absent, mild, moderate or severe. Results: There was mild bacterial growth at all intervals in group I; however, in group II there was severe growth at 7 days and no growth (absence) at 14 and 30 days. Conclusions: We conclude that the phytotherapeutic agent extracted from a fraction of AcOEt of A. lappa presented inhibition of all the studied microorganisms.