Clean and “Minty”

Mouth bacteria are a major cause of cavities and oral diseases. A large portion of people use mouthwash to rid the mouth of bacteria. I wondered if an herbal mouthwash would be as effective as a conventional mouthwash against bacteria. My hypothesis was that making a mouthwash of Oregano Oil will be more effective than traditional mouthwash in killing Staphylcoccus epidermidis, bacteria found typically on human skin, but also in the mucous membranes of the mouth. I grew S. epidermidis in Luria broth and made a lawn on nutrient agar quad petri dishes by dispensing 125 µL of the Luria broth and bacteria mixture and then swabbing the surface of the nutrient agar to spread the bacteria to create the lawn. I then placed a 10 µL drop of the controls (both water and olive oil—used to dilute the Oregano Oil) and then applied the treatments of mouthwash with alcohol, mouthwash without alcohol and different dilutions of Oregano Oil. The next morning I outlined the area of inhibition by drawing around the clear areas in the petri dish on clear film graph paper. I then counted the squares, and calculated the area of inhibition. I analyzed my data using ANOVA single-factor analysis and the 17 to 20% dilutions of Oregano Oil were statistically different than the other trials.