When it comes to cleaning your teeth, the rules are pretty clear-cut: the American Dental Association recommends brushing for two minutes twice a day with fluoride toothpaste —anything less will compromise the health and appearance of your teeth.
But your toothbrush also needs specific care to keep your teeth their healthiest. “Ignoring the importance of changing your toothbrush regularly can leave you vulnerable to a buildup of bacteria and germs,” warns Chris Kim, D.D.S. of the Virginia-based practice Livewell Dental. “Not only can this lead to bad breath and plaque buildup, but it can also put you at risk for infections and illnesses.”
So, how often should we actually change our toothbrush?
“Both manual toothbrushes and electric brush heads should be replaced every three months, and/or after each time you're sick (whichever comes first),” says
Whitney DiFoggio, R.D.H. (registered dental hygienist).
This is because “when your toothbrush gets old, the bristles start to harden or fray [and] can no longer effectively clean your teeth, since bristles need to slightly flex when brushing,” DiFoggio explains. In addition, “Toothbrush bristles tend to accumulate germs and can breed bacteria if you use them while you're sick.”
Best to toss your brush or brush head when you’re feeling better — many experts believe this may protect you against reinfection, although the Centers for Disease Control and Prevention (CDC) reports that there is no published research to support this.
How do I know my toothbrush needs replacing?
While three months is the recommended amount of time to keep a toothbrush or toothbrush head on an electric toothbrush, keeping an eye out for frayed, worn-out looking bristles (or any other changes such as discoloration or odor) can also be a good barometer of when it needs to be replaced. In fact, one study looked at wear and tear on a toothbrush, and found that toothbrushes with the most wear left brushers with more plaque on their teeth, even though the brushes were only three months old.
But even if it looks sprightly, the brush could be accumulating things you can’t see — and certainly don’t want anywhere near your mouth. “Simply put, failing to replace your toothbrush (or toothbrush head) frequently puts you at risk for unnecessary exposure to many strains of bacteria, including some nasty, pathogenic bacteria and viruses,” says Kansas-based dentist Jordan Weber, D.D.S.
Why do I need to change my toothbrush at least every three months?
If you must know, these major icks get onto the bristles because of other things you do in the bathroom, especially if you don’t close the toilet seat when you flush, says Dr. Weber. “If you leave any toothbrushes, oral care products, hair care products or other beauty products uncovered on a bathroom countertop, you really should be closing the toilet lid prior to flushing the toilet [because] the research on the topic of microbial hazards of flushing a toilet is, frankly, quite unpleasant to read,” Dr. Weber explains. “Ultimately, your toothbrush either needs to be covered, or else the toilet lid needs to be closed prior to flushing.”
DiFoggio agrees: “If you don't put the toilet seat down before you flush, E. coli bacteria droplets (from residual fecal matter) in the toilet bowl water can actually splatter throughout the air (five to six feet from most toilets) in your bathroom and land on your toothbrush.”
Thoroughly grossed out yet? But wait, there’s more! A bout with an illness such as a stomach bug or other kind can leave even a new toothbrush with potentially harmful bacteria. Experts worry this can lead to reinfection, and while currently there are no published studies to support this, it does seem like a good idea to start fresh after a bout with the sickies.
How often should you sanitize your toothbrush?
In addition to changing your toothbrush every three months and after an illness, keeping it clean and sanitary is also important. “Try to rinse your toothbrush with super steamy water after every use to flush away and kill whatever is already lurking between your bristles,” she says. “Then shake as much of the water out as you can and store it upright," says DiFoggio.
If you want to go above and beyond with keeping your toothbrush clean, she says, it can't hurt to sanitize it once a week. Soak your toothbrush head down in antimicrobial mouthwash for 30 minutes, then let it air dry, or try the same approach with an effervescent denture cleaner. Distilled vinegar or hydrogen peroxide can also work, she says. Just remember that while sanitizing can help keep your toothbrush clean, replacing it with a fresh one every three months is still recommended.
What happens if you don’t change your toothbrush for a year?
There is no research on this subject, and there’s a chance nothing bad will happen, but for all the reasons mentioned above — gross bacteria and germs, ineffective worn bristles that’ll leave plaque on your teeth — you may develop tooth decay or catch a bug if you don’t change your toothbrush for a year. And DiFoggio also recommends going for a pro cleaning appointment every six months (where you’re bound to get a new toothbrush — bonus!).
The bottom line: It is strongly recommended that you change your toothbrush or toothbrush head every three months, when the bristles are worn or frayed, or if you become ill. Rinsing in hot water and sanitizing in mouthwash is also a good idea. If you’re daunted by the notion of adding one more “to-do” to your calendar, consider a subscription service timed to mail you a new toothbrush four times a year, or set a reminder for yourself. “There are ways to stay on top of this often-overlooked task,” says Dr. Kim. “Subscription services and phone reminders can help you stay consistent with your toothbrush replacement schedule and ensure you always have a fresh toothbrush on hand.” Keeping a couple of extras around in case a bug strikes your household or a toothbrush suddenly starts showing its wear and tear is also a genius move.
Luisa Colón
Luisa Colón is a Brooklyn-based writer whose work has appeared in The New York Times, Family Circle, USA Today and many other print and online publications. Herfirst novel, Bad Moon Rising, will be released in August 2023.