Appropriate toothbrush storage and care are important to achieving personal oral hygiene and optimally effective plaque removal, said Maria L Geisinger, assistant professor of periodontology in the School of Dentistry at the University of Alabama at Birmingham.
"The oral cavity is home to hundreds of different types of microorganisms, which can be transferred to a toothbrush during use," Geisinger said.
"Furthermore, most toothbrushes are stored in bathrooms, which exposes them to gastrointestinal microorganisms that may be transferred via a fecal-oral route.
"The number of microorganisms can vary wildly from undetectable to 1 million colony-forming units (CFUs). Proper handling and care of your toothbrush is important to your overall health," she said.
Geisinger said that enteric bacteria, which mostly occur in the intestines, can transfer to toothbrushes and thus into your mouth.
This may occur through inadequate hand-washing or due to microscopic droplets released from the toilet during flushing.
Geisinger advised that people should thoroughly rinse toothbrushes with potable tap water after brushing to remove any remaining toothpaste and debris.
"Additionally, soaking toothbrushes in an antibacterial mouth rinse has been shown to decrease the level of bacteria that grow on toothbrushes," she said.
"The American Dental Association recommends that you not store your toothbrush in a closed container or routinely cover your toothbrush, as a damp environment is more conducive to the growth of microorganisms.
"Also, storing toothbrushes in an upright position and allowing them to air dry until the next use is recommended, if possible. If more than one brush is stored in an area, keeping the toothbrushes separate can aid in preventing cross-contamination," Geisinger said.
Geisinger said toothbrushes should be replaced at least every three to four months or when bristles become frayed and worn, whichever comes first.