When a person is sick with a cold, the flu, or another contagious illness, the toothbrush used during that time can harbor viruses and bacteria on its bristles. The moist environment of a bathroom, combined with oral microorganisms, creates a prime location for these pathogens to survive for hours or even days. Maintaining proper toothbrush hygiene after recovering from sickness is a significant step in preventing potential reinfection and cross-contamination.
When to Discard the Toothbrush
The decision to discard a toothbrush versus disinfecting it depends on the type of illness and its severity. Health professionals often advise replacing the toothbrush after a highly contagious bacterial infection, such as strep throat, to minimize recurrence risk. After recovering from a severe viral infection like COVID-19 or influenza, the safest approach is to replace the brush head once symptoms have fully resolved.
While some studies suggest that bacteria may not survive long enough on bristles to cause reinfection, the cautious recommendation is to replace the brush after the worst symptomatic phase of any illness. If the toothbrush bristles are visibly frayed or damaged, replacement is necessary regardless of illness.
Approved Methods for Disinfection
If the illness was a mild cold and the toothbrush is relatively new, disinfection can be an effective alternative to replacement. One reliable method involves soaking the bristles in 3% hydrogen peroxide solution. To prepare this, mix one part of the standard 3% hydrogen peroxide with three parts of water and submerge the bristles for about 10 to 15 minutes. The resulting bubbling action helps to physically lift and eliminate microorganisms from the brush fibers.
Another accessible option is to use an antimicrobial mouthwash that contains ingredients designed to kill germs. After brushing, rinse the toothbrush and then soak the head in a small cup of antibacterial mouthwash for at least 30 seconds. Make sure the mouthwash is specifically labeled as antibacterial or antiseptic for this method to be effective. Always rinse the brush thoroughly with clean water after using any chemical disinfectant to remove residual solution before the next use.
For a heat-based method, briefly dipping the toothbrush head into boiling water can sanitize the bristles. Submerge only the head for approximately five to ten seconds. Extended exposure to high heat can damage the plastic handle and melt the synthetic bristles.
Ongoing Hygiene and Storage Tips
Maintaining proper daily storage is the primary defense against microbial buildup on a toothbrush. After each use, rinse the brush thoroughly with tap water to remove any remaining toothpaste and debris. Store the brush in an upright position in an open-air holder to allow the bristles to dry completely between uses.
A moist environment encourages the growth of bacteria and mold. Avoid storing a wet toothbrush in a closed container, medicine cabinet, or travel case. For shared bathrooms, keep individual toothbrushes separated so the bristles do not touch. Replace the toothbrush every three to four months, or as soon as the bristles look matted or frayed.