How Gross Is It Really To Share a Toothbrush With My Partner?

There are people completely unfazed by using their partner’s toothbrush—whether it’s a one-time thing or a regular occurrence—and those who are totally repulsed by the idea. No matter which camp best describes you, know that sharing definitely isn’t caring when it comes to your oral hygiene.

But if you do borrow your partner’s toothbrush from time to time, your’e not alone: In a survey of more than 1,100 Match.com members, the online dating platform found that 22 percent of the participants admitted to doing it—and 76 percent of ’em never even told their partners about the bristly encounter.

The habit might not seem all that bad—you’re sharing with a person you regularly smooch after all. But according to orthodontist Ana Castilla, DDS, swapping spit and swapping brushes aren’t the same thing—like, at all. And that’s why she would never, ever recommend it.

“The mouth is home to hundreds of different species of bacteria and occasionally some viruses that can easily be transferred from one person to another by sharing a toothbrush, including the culprits for colds, flu, herpes, and even periodontal disease,” says Dr. Castilla. “To kiss someone is one thing. To pick up the plaque and bacteria off of someone’s teeth and then scrub it on your own is quite another.”

“To kiss someone is one thing. To pick up the plaque and bacteria off of someone’s teeth and then scrub it on your own is quite another.” —Ana Castilla, DDS

When you kiss someone, you’re mostly sharing saliva, Dr. Castilla says. When you use someone else’s toothbrush, though, there’s a chance you could be introducing bacteria or viruses they’re harboring into your own bloodstream. “This is because for many people, brushing can result in bleeding of the gums, especially if that person has gingivitis or periodontal disease, the latter affects 47 percent of those age 30 and older in the U.S., according to the CDC,” she says. “Even if you believe both of you are perfectly healthy, when it comes to bacteria and spreading infection, it really is a matter of numbers. The less bacteria that’s being spread around, the better it is for everyone involved.”

And it doesn’t matter if a toothbrush looks clean and it stored properly. Regularly disinfecting your toothbrush isn’t necessary, but bacteria invisible to the naked eye hides everywhere. “The snake-like microscopic bacteria get stuck in between bristles,” says Nammy Patel, DDS. So the next time you’re in a pinch without a toothbrush, use your (sanitized) finger and then run out to get yourself a toothbrush. It’s better than getting a mouthful of problem-causing bacteria any day.