Abstract
Colonization of bacteria causes various diseases of oral cavity such as plaque and gingivitis. Staphylococcus and Streptococcus species are the most important pathogens causing dental caries. The present study was designed to screen the anti bacterial action of four different marketed mouth washes namely Listerine zero, Colgate plax, Signal expert protection and Aloe dent against selected human pathogenic strains Staphylococcus aureus, Streptococcus pyogenes, Bacillus subtilis and Escherichia coli. All the brands of mouth wash demonstrated an excellent spectrum of activity against Staphylococcus aureus. In this study the antibacterial action of Listerine zero was significant when compared to Colgate plax against Staphylococcus aureus at P <0.05 level. However, the spectrum of action of Colgate plax was extremely significant against Bacillus subtilis at P<0.001 level when compared to rest of mouthwashes screened. The spectrum of activity varied with brands of mouth washes screened against organisms. This study demonstrated that all the brands of mouth washes revealed good anti bacterial effect.