Can you remember the last time you replaced your toothbrush? If your dentist gives you a new one every visit, maybe it was within the last six months. But if they don’t—or if you’re guilty of skipping those routine cleanings—your brush might be languishing.
The American Dental Association (ADA) recommends replacing toothbrushes every three to four months, or sooner if they have visible signs of damage. But “I would assume that most people keep their toothbrushes longer than recommended,” says Iwonka T. Eagle, director of the graduate dental hygiene program and a clinical associate professor in the department of periodontics and oral medicine at the University of Michigan School of Dentistry. “I always tell patients, if you can’t remember when you replaced the brush last, then it’s probably time.”
“I think people typically go about every six months,” says Dr. Lee Weisbard, owner of Weisbard Dental in Greenwood Village, Colo. “In our practice, we give people a new toothbrush or we replace their toothbrush head. So I think a lot of people just wait until they go to the dentist and get a new toothbrush. But we try to tell them that they should replace it every three to four months.” If your dentist doesn’t give you a new toothbrush, your regular cleaning should be a reminder to replace yours on your own, although even sooner would be better, she adds.
Why every 3 to 4 months?
Sometimes people think replacing their toothbrush is a matter of hygiene—that an older brush is harboring bacteria and other microbes that might make them sick. But experts say the primary reason to replace your toothbrush frequently is because it loses effectiveness.
“The bristles just wear out. The more we use it, especially if people are brushing too hard, those bristles are going to become frayed or bent or splayed,” Eagle says. “As they become worn out, they become less effective at removing plaque from tooth surfaces, especially at the gum line. Worn bristles are just not going to contact the tooth surfaces as predictably or as accurately.”
Over time, if you’re not removing as much plaque, your risk of tooth decay, inflammation, or infection can increase, says Dr. Ada Cooper, a consumer advisor spokesperson for the American Dental Association with a private dental practice in New York City.
Plus, brushing with bent bristles might also hurt sensitive gums, especially if you’re doing so with a lot of force. “This can cause tissue irritation because the worn-out bristles can scratch your gums, and can lead to receding gums and sometimes even bleeding,” she says.
The same rule applies if you’re using an electric toothbrush. Replace the head about every three months, or sooner if the bristles are visibly worn down, Eagle says. Some brushes or brush heads even have colored indicator bristles that will fade when it’s time for a replacement, she adds.
And though it may not be the primary reason to change your toothbrush, microbes still matter. “Flat and matted bristles tend to hold water longer, and so worn-out bristles can sometimes become more porous, creating ideal hiding spots for bacteria,” Cooper says.
Some dentists recommend replacing your toothbrush after any time you’ve been sick. But you probably don’t need to do this if you’re generally healthy and you just had a regular cold, per the ADA. “[Some] people feel more comfortable switching their toothbrush out because it grosses them out,” Eagle says. “It’s a low-cost precaution to feel better, but most likely you’re not going to reinfect yourself with your toothbrush.” To be extra safe, Eagle and Weisbard recommend replacing your toothbrush after any serious illness, like COVID, or any infection in your mouth, like strep throat.
Other signs it’s time to replace your toothbrush include an odor on the brush that lingers despite cleaning it or visible debris clogging the bristles, Eagle says. And you’ll probably want to toss it if it falls somewhere dirty, she adds.
How to take good care of your toothbrush
Treating and storing your toothbrush properly can help ensure it lasts for those three to four months. Rinse it right after you brush to get rid of any remaining toothpaste or debris. Store it upright, making sure it’s not touching anyone else’s toothbrush, so it can dry out between uses, Cooper says. “Don’t routinely cover your toothbrushes or store them in closed, dark containers, because a moist environment, like a closed container, is more conducive to the growth of unwanted bacteria than in the open air,” she says. Don’t toss your toothbrush in a drawer, either, Weisbard says.
If you’re traveling and using a toothbrush cover or case, store your toothbrush outside of the container once you reach your destination, Eagle adds.
While you might have more pressing items on your to-do list, replacing your toothbrush regularly helps ensure you’re taking good care of your oral health. And if you tend to lose track of the last time you got a new toothbrush, consider creating an event on your digital calendar or some other reminder on your phone to keep you on track, Eagle says.
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