Abstract

Dental plaque, biofilms of microorganisms on tooth surface, plays an important role in the development of caries and periodontal disease. Our aim was to test in vitro antibacterial activity of some herbal extracts against Actinomyces viscosus, Streptococcus mutans,Streptococcus sobrinus, Lactobacillus fermentum, Lactobacillus casei and Eikenellacorrodens. Hydro alcoholic (50:50) extracts of 6 plants were taken using succilate method, then 4 dilutions of extracts (20, 40, 80, and 100% w/v, mg/ml) were put on blood agar media and cultured with one of the bacteria using 4 mm paper discs. Antimicrobial activities of these extracts were examined by disc diffusion method and mean of diameters of inhibition zone of each bacterium in different dilutions was reported. (P<0.05) hydro alcoholic extracts of Punica granatum and Trigonella foenum-graceum had strong antibacterial activity respectively, and their antibacterial activities were significantly less than Chlorhexidine and more than Irsha and Miswak. The hydro alcoholic extracts ofScrophularia striata and Fumaria parviflora showed less antibacterial activity in comparison with the first two and it was significantly less than Chlorhexidine and Miswak and more than Irsha. Carthamus tinctorius had the weakest antibacterial activity. We recommend more studies to demonstrate practical approaches of using natural materials on the oral biofilms.

Key words: Herbal extracts, antibacterial, dental plaque, chlorhexidine, essential oils.