The Effect of Alcohol Content, Hydrogen Peroxide Content and Cetylpyridinium Chloride Content on the Effectiveness of Bacteria Killing Mouthwash

This experiment tests how alcohol content, hydrogen peroxide content and cetylpyridinium chloride content in different mouthwashes affects the amount of bacteria the mouthwash kills.  In order to perform this experiment the researchers first put 5 ml of mouthwash into a vial.  The researchers used the inoculating loop to put a sample of Micrococcus luteus in the mouthwash.  Then the researchers put the bacteria and mouthwash solution in a Petri dish and put it in the incubator to grow.  The researchers checked back after 48 hours and counted the colonies of bacteria in the mouthwash.  The ANOVA test showed that there was a significant difference in the means of the data sets.  From this test the researchers could see from the graphs that the mouthwash that had alcohol content, hydrogen peroxide content and cetylypridinium chloride content killed the most bacteria.  The mouthwash that was the second most effective in killing bacteria was the mouthwash with alcohol content, hydrogen peroxide content and no cetylypridinium chloride content.  The mouthwash that did not have alcohol content, did not have hyrdrogen peroxide content and did not have cetylypridinium chloride content killed the least amount of bacteria.  From the results the researchers could see that the component that had the greatest impact on killing bacteria was alcohol.

Research Done By:

Rebecca Russell
Warren Mott High School

Erin Smith
Warren Mott High School