Next time you’re considering a passionate embrace, you might want to consult your partner’s dental records.
A Houston dentist is confronting TikTok with a brutal truth: you can get cavities from kissing the wrong person. “Thinking about the kiss I gave my husband even though he has cavities,” Dr Tasneem Mahmood writes in her video, captioned: “And that’s on cavities being contagious.” The clip has been viewed more than a million times.
It seems weird – how could a void in your tooth result in a similar crater in the mouth of a lover? But to dentists, it’s not exactly breaking news.
Experts have been aware of the transmissibility of tooth decay since at least the 1970s, according to Dr John Featherstone, professor emeritus and former dean of the School of Dentistry at the University of California, San Francisco.
Decay is linked to the presence of certain bacterial strains in our mouths, and that bacteria can be exchanged between people through the saliva – by, say, kissing.
In 2011, a dentist told the New York Times about a patient in her 40s who had never had a cavity – until she started seeing a guy who hadn’t visited the dentist in 18 years. Featherstone, who has spent four decades investigating the management of tooth decay, has seen similar cases in his own research.
But the bacteria don’t do the job on their own. “The second absolutely essential thing for tooth decay is frequent ingestion of what we call fermentable carbohydrates. So sucrose, glucose, fructose, high fructose corn syrup and bread for that matter,” Featherstone says.
The bacteria feed on the carbohydrates that we unwittingly provide for them, and they produce acid in the process. This acid dissolves the calcium phosphate in our teeth and leads to decay.
So even if your partner does give you some of these bacteria, you can improve your odds of staying healthy by following good dental practices. That includes avoiding excessive ingestion of these risky carbohydrates, maintaining “very low frequency of ingestion of sugars during the day in between meals”, Featherstone says. It also means “brushing twice a day with a fluoride-containing toothpaste”. (Here’s a much more detailed account of Featherstone’s findings, aimed at providers but with useful information for patients.)
“Most of us have these decay-producing bacteria in our mouths,” says Featherstone. “I do. And I don’t have tooth decay – I haven’t had it for decades.”
That doesn’t mean we should let dental nightmares stop us from expressing love, Featherstone says. “Kissing is a really good way to pass on any disease from one to another. So I think it’s very important not to say that kissing is bad, because it’s part of humans’ activity.”
Mahmood agrees, telling Insider she isn’t advising against kissing people with cavities. “Not at all,” she tells the site. “Having cavities is not a moral failing.”
Still, Featherstone says, “be careful if your partner has lots and lots of decay. They are going to transmit to you.” You’ll need to take extra care with your hygiene. “So if your partner is loaded with active decay, do send them to a dentist and get it fixed.”