1. Mouthwash Effectiveness Against Oral Bacteria David A. Adams Microbiology Undergraduate Tennessee Technological University Cookeville, TN 38505

2. Introduction Undesirable oral odors generally come from proteins and peptides hydrolyzed by gram- negative bacteria (McDowell 1993) Undesirable oral odors generally come from proteins and peptides hydrolyzed by gram- negative bacteria (McDowell 1993) Bacteria in the mouth are primarily responsible for gingivitis (Journal of American Dental Association 1998) Bacteria in the mouth are primarily responsible for gingivitis (Journal of American Dental Association 1998) The number of viable bacteria dropped by 94% after rinsing with antiseptic mouth rinse (Fine et al 1993) The number of viable bacteria dropped by 94% after rinsing with antiseptic mouth rinse (Fine et al 1993)

3. Objective The objective of this research was to determine the susceptibility of bacteria to different brands of mouthwash The objective of this research was to determine the susceptibility of bacteria to different brands of mouthwash Hypothesis Rinsing with mouthwash will have no benefit over rinsing with water to prevent bacterial growth. Rinsing with mouthwash will have no benefit over rinsing with water to prevent bacterial growth.

4. Methods & Materials Methods were derived from Dr. Goss’ 2004 Medical Micro lab manual Methods were derived from Dr. Goss’ 2004 Medical Micro lab manual 3 TSA plates inoculated with 3 different oral bacteria for 24 hours 3 TSA plates inoculated with 3 different oral bacteria for 24 hours Three individual mouthwashes (A, B, C) tested Three individual mouthwashes (A, B, C) tested Water used as control (D) Water used as control (D) Performed three trials & took average Performed three trials & took average

5. Methods & Materials A D C BA D C BA D C B StaphylococcusEscherichiaPseudomonas Legend: A=Control B=Scope C=Listerine D=Equate

6. Results Bacterial Inhibition

7. Results

8. Discussion Staphylococcus was the least resistant bacteria Staphylococcus was the least resistant bacteria Pseudomonas and Escherichia were equally resistant Pseudomonas and Escherichia were equally resistant Better results may be obtained by testing a greater number of different oral bacteria Better results may be obtained by testing a greater number of different oral bacteria

9. Conclusion All 3 mouthwash brands inhibited bacterial growth All 3 mouthwash brands inhibited bacterial growth The generic brand mouthwash, Equate, was the most effective The generic brand mouthwash, Equate, was the most effective More cost does not always equal better value More cost does not always equal better value

10. Questions?