Blog Assignment #8: Research Project Update: The Effects of Mouthwash on Bacteria

The Effects of Mouthwash on Bacteria

Team Members: Greyson Hamilton,Hazel Hosseini, Michelle Le, Eloina Rodriguez

Trial 1 Trial 2

• Update us about the current state of your research project.

Our research project is going well, we have recorded two sets of results with only minor deviations. Our data has found crest clinical to be the best at inhibiting growth in bacteria. While we are also testing CPC, an agent found in crest clinical, which has been effective at inhibiting growth, it still underperforms in comparison. One of our samples had inhibited growth with our control, which had no inhibition recorded in the first trial, we are going to run the experiment again under the same conditions to deduce if the inhibition on the control plate was an error on our part or if the bacteria on that plate is inhibited by DI water.

• Tell us about your initial results!

Trial 1

	Bacteria from MLT	Bacteria from GH	Bacteria from ER
D.I. Water	0 mm	0 mm	0 mm
CPC 0.01%	69 mm	28 mm	11 mm
Crest Clinical	23 mm	35 mm	20 mm
Crest Scope	12 mm	22 mm	18 mm
Listerine Naturals	0 mm	0 mm	7 mm
Listerine Zero-Alcohol	7 mm	14	7.5 mm

Trial 2

	Bacteria from MLT	Bacteria from GH	Bacteria from ER
D.I. Water	0 mm	8 mm	0 mm
CPC 0.01%	23 mm	18 mm	19 mm
Crest Clinical	34 mm	38 mm	26 mm
Crest Scope	37 mm	13 mm	13 mm
Listerine Naturals	0 mm	0 mm	8 mm
Listerine Zero-Alcohol	7 mm	13 mm	7 mm

We have measured the zones of inhibition for 2 trials. In both trials Crest Clinical was the most successful at inhibiting the growth of bacteria from Greyson (GH) and Eloina (ER), but was not the most successful against the growth of bacteria from Michelle (MLT). In trial 1, Cetylpyridium Chloride 0.01% was the most effective at inhibiting bacterial growth from Michelle’s bacteria, but in trial 2, Crest Scope was the most effective. In comparison, Listerine Naturals was consistently the least effective against bacterial growth in trial 1 for all three bacterial specimens, with an exception in trial 2 on the bacterial culture from ER.  In trial 2, our DI water control on the culture from GH had an inhibition zone of 8mm which has had a 0mm measurement, or no inhibition of bacteria, in all other specimens of both trials.

• Have you had any revisions to your experiments?

We had some data in the second trial that did not match up with the results of the first trial. So we decided to quantify how much mouthwash we use per cotton disc (35 µL) opposed to our original procedure which had us soak the discs in mouthwash/DI water/Cetylpyridium Chloride for 15 minutes. We hope this will allow us to keep our results more consistent, we might revise what we are testing with the bacteria if our results concur with previous trials.

• What do you have planned for the final 2 weeks?

We are confident that trial 3 will have more accurate results because we will be controlling the amount of mouthwash/DI water/CPC better than in our initial two trials. If our results are very contradicting to the previous two trials, then we are considering setting up a fourth trial. Otherwise, our group will be starting to work on designing our poster and how best to present the results and data from our experiment.