Always store your toothbrush in a travel container.
Dry your toothbrush after use and before returning to its container.
Change the toothbrush you take to work more often than your toothbrush at home to avoid bacteria build-up.
How to Store a Toothbrush
Splattering water, contact with skin and toothbrushes knocking against one another are all circumstances that contribute to the spread of bacteria. Dr. Glazer recommends rinsing bristles thoroughly, then shaking any extra moisture from the brush and storing it upright before placing a cover over the toothbrush head.
Bacteria from food particles and contact with the skin are unavoidable consequences of daily brushing. Dr. Glazer says people should wash their hands both before and after brushing, and soak unused brushes in an antiseptic mouthwash. Having more than one toothbrush makes this process a lot more practical. “The bathroom is usually the most contaminated room in the house,” says Dr. Glazer. “Protect yourself by protecting your toothbrush.”