This dentist says cavities are contagious – but can you catch them through kissing? Experts weigh in

You can catch more than just feelings from kissing, according to an American doctor. Houston-based dentist Dr Tasneem Mahmood has caused a social media uproar after she claimed cavities are contagious.

“Thinking about the kiss I gave my husband even though he has cavities,” she writes in her now viral video on TikTok. The video was captioned, “And that’s on cavities being contagious.”

Her comment was news to her followers, with many just plain horrified at the thought. “Why do I have to learn this stuff on TikTok,” someone said on social media.

“Really, now I have this to worry about too,” another commented. “Excuse me? I'm never kissing anyone again,” said a third.

The video, which racked up 1,2 million views, has made people question if they have ever “caught” cavities from their partners before.

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But is her claim actually true?

Oral hygienist Iman Vancamelbeke from Dainfern Dental Studio in Johannesburg says the TikTok dentist’s comments should be taken with a pinch of salt.

“Cavities are not transmissible nor are they contagious. The bacteria that causes cavities may be transferred during the exchange of saliva in kissing, sharing utensils and so on,” she says.

The bacteria don’t do the job on their own, however. “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,” says Dr John Featherstone, former dean of the School of Dentistry at the University of California, San Francisco, in the US.

The bacteria feed on the carbohydrates, producing acid in the process. This acid dissolves the calcium phosphate in our teeth and leads to decay, which can cause cavities and bad breath.

So how do you keep your pearly whites healthy and whole? Iman suggests you reduce your sugar intake as well as frequency. “Instead of sipping on a can of soda the entire day, finish it in one sitting, for example,” she says. 

She also recommends brushing with a fluoridated toothpaste.

Fissure sealants (a resin that usually contains fluoride that’s put into the fissure of your molars and premolars) are also helpful to prevent cavities. 

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If you already have cavities, fillings are effective. There are several dental filling materials available. Teeth can be filled with gold, porcelain, silver or tooth-coloured plastic and a material called composite resin fillings.

Your dentist can recommend the best treatment to restore your teeth depending on the extent of the damage.

At home, however, brushing twice a day and practicing good oral hygiene is always advised.

Sources: TikTok, theguardian.com, businessinsider.co.za, dailymail.co.uk