Replace toothbrushes at least every 3–4 months. And if you've only had your toothbrush for 1 month, and you have a cold or sinus infection, throw it away. There is no reason to re-infect yourself from using this toothbrush. Throwing your toothbrush out after 3 months seems like a short time, but think of the germs, viruses and bacteria it is exposed to daily.
The bristles become frayed and worn with use and cleaning effectiveness will decrease. Toothbrushes will wear out more rapidly depending on factors unique to each patient. Check brushes often for this type of wear and replace them more frequently if needed. Children’s toothbrushes often need replacing more frequently than adult brushes. You can also kill germs by soaking your toothbrush in an antiseptic mouthwash or hydrogen peroxide for about an hour, then rinse it and dry it.
Toothy Truths (useless, but fun information)
Did you know your old toothbrush can be your latest fashion accessory? Check out how to make a toothbrush bracelet. I bet you'll be the only one on your block with one (hopefully). http://bit.ly/zpAV3