Investigation to determine the effect of different brands of mouthwashes on microbes

Order of Zone of Clearance of Microbial Decay (Highest to Lowest)

1. Mouthwash A – Colgate Plax
2. Mouthwash C – Listerine
3. Mouthwash B – Dentyl Active
4. Mouthwash D – Superdrug

   

   

Figures 1 to 3 show photographs of some of the results I collected from the pilot investigation. You can clearly see that different brands of mouthwash had different effects on the microbes as some destroyed them more than others and this is shown by a ring of clearance around each sample of mouthwash on the filter paper. Figure 4 shows a close up of one of the samples with arrowheads showing the distance that I measured for each brand of mouthwash using the digital callipers. I have included these photographs for evidence of the results shown in the table for my pilot investigation.

When looking at the results table and the zone of Clearance order I can see that Mouthwash A had the highest average zone of clearance followed by Mouthwash C, then B and lastly D. This shows that from the pilot investigation, Mouthwash A was the most effective in destroying the Microccus Liteus microbes. When looking at the average result, it is almost double that of Mouthwash D.  

Once I had completed this pilot experiment, I then decided to see what the effect of mouthwash would be with another type of bacteria to see if the same mouthwashes would act in the same way and produce the same results as I got in the pilot investigation. The bacteria that I used wanted to use was E-coli so in the real investigation I used E-coli bacteria as well as Microccus Liteus to produce results for investigating the effect of different brands of mouthwash on bacteria.

 

Results For E-Coli

Order of Zone of Clearance of Microbial Decay (Highest to Lowest)

1. Mouthwash B
2. Mouthwash C
3. Mouthwash A
4. Mouthwash D

Results For Microccus Liteus

Order of Zone of Clearance of Microbial Decay (Highest to Lowest)

1. Mouthwash A
2. Mouthwash C
3. Mouthwash B
4. Mouthwash D