Title: Testing the effectiveness of alcohol and alcohol-free mouthwashes against bacteria Introduction: Many of these products claim to do the same thing: kill bacteria. It's worth looking at what these products actually do, versus the claims made about them. Although many of these products promise to feature a 0% bacteria end environment and fresh breath, the accuracy of this claim is highly dependent on the ingredients present in their composition. the solution. Alcohol is a very common ingredient in most mouthwashes due to its powerful antibacterial effects. It has been used for many years by the biggest oral care brands. While this is a positive effect of alcohol in mouthwashes, many mouthwashes containing alcohol have been proven to cause other health problems such as mouth dry, etc. So, although alcohol mouthwashes kill a large portion of the bacteria, they have no effect on the end result of the ongoing problem of bad breath. Therefore, mouthwashes without alcohol but containing another bactericidal agent are more effective. Recent studies by Maria Perno Goldie, RDH, MS showing that "alcohol-containing products like Listerine ended up reducing bacteria in patients by between 13 percent and 56 percent, while alcohol-free rinses, such as Colgate Pro-Health, had a 15% effect on bacteria. (Goldie, 2013)For this experiment, a range of mouthwashes were used to test whether alcohol-based mouthwashes are more effective than alcohol-free mouthwashes. The products tested included two major brands most commonly found and used in the everyday home, Listerine and Colgate. Among these two brands, a selection of four mouthwashes was chosen - Two without alcohol...... middle of paper ......both bacteria. The final mouthwash tested, Listerine Zero, was found to be the least effective, with an average of 3.47058824 mm for S.albus and an average of 2.47647059 mm for E.coli. Not containing alcohol, it is the least effective. The results from the raw data in Figure 2 were then calculated into four averages and then presented in a graph in Figure 3. Figure 3 – Calculated averages of the recorded results. From Figure 3, it is clearly evident that Colgate Plax provided the best results and was most effective against E.coli and S.albus. Listerine Fresh Burst was second most effective against S.albus and third against E.coli. . Colgate Max White One was third most effective against S.albus and second against E.coli and Listerine Zero was least effective against S.albus and E.coli.