At some point, many people will be confronted with a dilemma. It’s time to brush your teeth, but you don’t have your own toothbrush handy. Maybe you’re traveling and forgot to pack it; maybe you accidentally dropped it in the toilet; maybe you just didn’t expect to be stuck somewhere without your toothbrush. So, after some internal debate, you make the decision to use someone else’s toothbrush. After all, it’s really no different than kissing someone ... right?
You might want to reconsider that position. Sharing a toothbrush is actually disgusting and the sooner you stop doing it, the better.
The official stance of the American Dental Association (ADA) is that toothbrushes should most definitely not be a communal hygiene item. “Sharing a toothbrush could result in an exchange of bodily fluids and microorganisms between people,” the ADA notes.
Is this advice simply out of an abundance of caution? After all, couples share saliva. But it’s not quite so simple. “Brushing sometimes causes the gums to bleed, which exposes everyone who shares one toothbrush to [bloodborne] diseases,” Dr. Ben Atkins, the former president of England’s Oral Health Foundation, told Women’s Health in 2019. “By sharing a toothbrush, couples may be sharing blood, which is a lot riskier than simply mixing saliva.”
Gums can become irritated and bleed for a variety of reasons, including overzealous brushing, using hard bristles, or diseases like gingivitis. Even if they don’t bleed, you’re still (literally) opening your mouth up to different kinds of bacteria and germs. A 2012 meta-analysis of toothbrush contamination research found that most supported the idea of toothbrushes harboring pathogens ranging from E. coli to herpes simplex type one (HSV-1) to cold germs.
Of course, just because a toothbrush can house germs doesn’t mean it can transmit them. That depends heavily on their survival on surfaces. Speculation that HIV could be transmitted through shared brushes has been debunked, for example, as the virus typically becomes inactive within a few hours of being outside the body.
Another bloodborne disease, hepatitis C, can technically be transmitted via a toothbrush provided it has “infectious blood,” per the U.S. Centers for Disease Control and Prevention. While the risk is low, it’s not zero.
In addition to keeping your toothbrush to yourself, it’s also important to keep it clean. Storing it upright so it can air-dry may reduce the germs collecting on the surface. (Keeping the brush covered in a container isn’t a good idea.) It’s also recommended to replace your toothbrush every three to four months, or whenever the bristles begin to splay.
There is one safe method for sharing a toothbrush. If you have an electric brush, families can use the handle and swap out their own heads. This can also save money, as you’ll only need one motorized brush for the household. (However, it’s still important to thoroughly clean the handle after each use.)
In summation: No, brushing is not the same as kissing. One involves an exchange of saliva, and the other involves scrubbing germs into your mouth. If you want a healthy relationship, it's best to keep your brushes separate.
Still need convincing? Click here to read about some of the other gross things that could be hiding in your toothbrush, from HPV to candida.