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Updated: May 29, 2026

Purification of a High Molecular Mass Protein in Streptococcus mutans
Published on: September 14, 2019
Disinfection of toothbrushes contaminated with Streptococcus mutans
Kim Bélanger-Giguère1, Steeve Giguère, Myriam Bélanger
1North Oconee High School, Bogart, Georgia, USA.
Purpose:
To determine the most effective method to kill Streptococcus mutans on contaminated toothbrushes.
Methods:
Seven toothbrushes (one for each treatment and the control) were contaminated with S. mutans. Toothbrushes were then rinsed in phosphate buffered saline (PBS) and treated as follows: (1) control without treatment; (2) air dry for 4 hours; (3) Crest Pro-Health mouthwash for 20 minutes; (4) Listerine mouthwash for 20 minutes; (5) normal cleaning cycle in a dishwasher; (6) microwave on high power for 5 minutes; and (7) ultraviolet light using the DenTek Toothbrush Sanitizer for 10 minutes. All toothbrushes were rinsed again with PBS. The bristles were cut and vortexed in PBS. Serial dilutions were performed and the number of colonies enumerated after incubation. The experiment was independently repeated seven times.
Results:
The Crest Pro-Health mouthwash and the dishwasher almost completely eliminated S. mutans. The second most effective treatment was the microwave. The Listerine mouthwash and the air dry groups were not significantly different from each other and ranked third. Although UV light significantly decreased the number of bacteria compared to the control, reduction in the number of S. mutans CFU was significantly lower than that of all the other treatments evaluated. Crest Pro-Health mouthwash for 20 minutes and a normal dishwasher cycle are the most effective methods to eradicate S. mutans from contaminated toothbrushes. Dent
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