Brian Freyvogel
Central Catholic High School
Grade 9
Crest Pro—Health Multi-Protection Mouthwash
•Active Ingredient:
▫Cetylpyridinium chloride0.07%
• Alcohol FREE
Scope Outlast Mouthwash
Active Ingredients:
Cetylpyridinium chloride0.07%
Alcohol based
Listerine Cool Mint AntisepticMouthwash
•Active Ingredients:
▫Eucalyptol 0.092%
▫Menthol 0.042%
▫Methyl salicylate 0.060%
▫Thymol 0.064%
•Claims to kill 99.9% of bacteria
•Alcohol based
TopCare Antiseptic Mouth Rinse
•Active Ingredients:
▫Eucalyptol 0.092%
▫Menthol 0.042%
▫Methyl salicylate 0.060%
▫Thymol 0.064%
•Alcohol based
Escherichia coli (E. coli)
•Large and diverse group of gram(-) bacteria
•Free living, symbionts, or pathogens
•Lives in the intestinal tract of many
mammals
•Serves as a common prokaryotic
cell model
•Commonly used as non-target
bacteria for testing of potential
antimicrobial abilities
Previous Studies
•According to Listerine’s official site, theydid an experiment in which they testedtheir product and it killed 99.9% ofbacteria.
• Research was also done by Shelby DentalCare, and this found Crest to be a moreadvantageous mouthwash than Listerine
Problem
•Is there a significant differencein the antimicrobial abilities ofthese mouthwashes?
Purpose
•To determine if there issignificant variation in the effectsof various mouthwashes on E. colisurvivorship
Hypothesis
•Null hypothesis:
▫ There will not be significant variation amongthe effects of the mouthwashes on thesurvivorship of E. coli
•Alternate Hypothesis:
▫There will be significant variation among theeffects of the mouthwashes on the survivorshipof E. coli
Materials
•Listerine Cool MintAntiseptic mouthwash
•Scope Outlastmouthwash
•Crest Pro-HealthMulti-Protectionmouthwash
•TopCare AntisepticMouth Rinse
•E. coli
•Spreader bars
•Open flame and ethanol(for sterilization)
•Various sized pipettes
•Sterile fluid
•Test tubes
•Vortex
•Incubator
•Klett Spectrophotometer
•Sidearm flask
Procedure
1.E. coli was grown overnight in sterile LB Media.
2.Samples of the overnight cultures were added to freshmedia in a sterile sidearm flask.
3.The culture was placed in an incubator (37°C) until adensity of 50 Klett spectrophotometer units wasreached. This represents a cell density of approximately10⁸ cells/mL.
4.All four mouthwashes were diluted into 2 test tubes,each with concentrations of 50% and 10%.
Procedure Cont.
Concentration
0%
10%
50%
Bacteria
0.1 mLs
0.1 mLs
0.1 mLs
Mouthwash
0 mLs
1 mLs
5 mL
Sterile Fluid
9.9 mLs
8.9 mLs
4.9 mLs
Total Fluid
10 mLs
10 mLs
10 mLs
Procedure cont.
5.0.1 mL of the bacteria was added to each tube,creating a 10^3 cells/mL cell concentration.The tubes were vortexed. Then 0.1 mL waspipetted to the Agar plate after exposure timesof 30 seconds, 1 minute, and 5 minuteswere reached. The plates were spread and placedin an incubator for 24 hours at 37°C.
6.The resulting cell colonies were counted. Allcolonies were assumed to have risen from onecell.
T-Values For 10% T-Crit: 2.18
Brand
T-Value
Listerine
-1.1814576 Insignificant
TopCare
-1.181473 Insignificant
Crest
-2.98520 Significant
Scope
-2.87297 Significant
T-Values For 50% T-Crit: 2.18
Brand
T-Values
Listerine
-2.21764 Significant
TopCare
-2.24736 Significant
Crest
-2.19573 Significant
Scope
-2.30857 Significant
Conclusions
REJECT NULL for:
Crest and Scope 10% concentration tests
All 50% concentration tests
T-Value of Scope and Crest was greater than theT-crit.
T-Value of Listerine and TopCare was lower thanthe T-crit.
Scope and Crest more effective, greaterantimicrobial ability
Limitations and Future Studies
Limitations
•Only two concentrationswere used
•Only three exposuretimes were used
•Only a single, non-targetbacteria was used
•Only liquid pulse wastested
•The mouthwashes werenot tested at full strength
Future Studies
•Use more mouthwashbrands
•Use higherconcentrations
•Test cost-efficiency
•Agar infusion tests
•Test more genericmouthwash brands
•Include test ofexposure time
•Test StreptococcusMutans
References
•Anayanwu, O. C., K.K. Baugh, S.B. Bennett J. M. Johnson, R.L. Madlock, N. E. Pollard, and J. O. Chikwem. “Comparisonof the Antimicrobial Effectiveness of Alcohol-Containing and Non-alcohol-containingMouthwashes.” Diss. Lincoln U, n.d. Abstract.. (n.d.): n.pag. Web.
•Aneja KR, Joshi R, Sharma C. The anti microbialpotential of ten most often used mouthwashesagainst four dental caries pathogens. JundishapurJ Microbiol. 2010; 3(1): 15-27
•Masadeh, Majed M., Shadi F. Gharaibeh, Karem H. Alzoubi,Sayer I. Al-Azzam, and Wasfi M. Obeidat. “AntimicrobialActivity of Common Mouthwash Solutions on Multidrug-Resistance Bacterial Biofilms.” N.p., n.d. Web.
ANOVA Results for 10% Concentrations
T-Critical=2.18
ANOVA Results for 50% Concentration
T-Critical=2.18
Colony Count Table by Exposure Time
