When you think about cavities, your thoughts might turn to sugary snacks or dental appointments. But here’s a curious question you might not have considered before: Can cavities be contagious?
While cavities themselves aren’t contagious, the bacteria that cause cavities can be shared between people through activities like sharing food and utensils.
What Causes Cavities?
Let’s start with the basics. Cavities are areas of tooth decay caused by bacteria like Streptococcus mutans and Lactobacillus. These bacteria feed on sugary or starchy foods, a process which produces acid that attacks and weakens your tooth enamel. Over time, this weakening can lead to holes, which we call cavities.
Key contributors to cavities include:
- A diet high in sugar and carbs – Sugars and starches fuel bacteria, allowing them to thrive.
- Poor oral hygiene – Skipping out on brushing and flossing allows bacteria to stay camped out on your teeth.
- Dry mouth – Saliva helps wash away bacteria and food particles, and a lack of it can create a bacteria-friendly environment.
By staying on top of your oral hygiene, you can stop these bacteria from making themselves at home in your mouth. Simple enough, right? Now, here’s the twist. The bacteria responsible for cavities can be transmitted from one person to another.
The Hidden Science of “Contagious” Cavities
While cavities aren’t contagious in the same way a cold or the flu is (you won’t catch tooth decay just by standing next to someone), the bacteria behind cavities can be spread. Here are some common pathways for transmission:
The Role of Saliva in Spreading Bacteria
The bacteria that cause cavities live in saliva. That means that actions like sharing a drink, using the same utensils, or even kissing can transfer these bacteria from one person to another. This is particularly common in close relationships—think parents and their young children or partners.
For example, if a parent dips their baby’s spoon into their own mouth, they may unintentionally transfer cavity-causing bacteria to the child. Studies even show that children often “inherit” their oral bacteria from their caregivers.
Close Contact and Sharing Habits
Do you share drinks, straws, or snacks with someone? Well, that sweet gesture could mean you’re also sharing oral bacteria. Couples who share everything except toothpaste—or share one toothbrush in an emergency—are at a higher risk for spreading cavity-causing bacteria.
Immune Variability Plays a Role
Not everyone responds the same way to these bacteria. Some people seem almost immune to cavities, thanks to genetics, better saliva quality, or exceptionally diligent oral hygiene. Still, introducing these bacteria increases the risk.
Who’s Vulnerable to “Catching” A Cavity?
Some groups are more vulnerable when exposed to cavity-causing bacteria:
- Babies and toddlers: Kids start life with a healthy, sterile mouth. That’s why early exposure increases their risk of developing cavities.
- Those with compromised oral hygiene: If your—or your child’s—brushing and flossing routine isn’t up to snuff, bacteria can multiply quickly.
- People with existing dental issues. If you already have cavities or gum disease, it could act as a “welcoming committee” for more bacteria when introduced into your mouth.
How to Prevent the Spread of Cavities
Here’s the good news—just because bacteria can spread doesn’t mean that your kids and/or partner are doomed to getting cavities themselves. A few simple strategies can help keep your teeth—and theirs—healthy and strong.
- Practice good oral hygiene. Brush and floss your teeth twice a day and keep up with regular dental appointments and cleanings.
- Avoid sharing utensils. In fact, avoid sharing any object that may have been exposed to saliva!
- Maintain a healthy diet. Minimizing the sugar in your family’s diet will limit opportunities for bacteria to grow.
- Use fluoridated toothpaste. Fluoride remineralizes the surface of the teeth and inhibits further growth of cavities. Note that, if your kids are young, you may need to help them brush.
What If You Already Have Cavities?
If you or a loved one has cavities, don’t panic. Your aim should be to stop the spread of bacteria and prevent further damage. Talk to your dentist about treatment options, which typically include fillings, fluoride treatments, or improving your oral care routine.
While cavities themselves can’t be “cured” at home, you can certainly support oral health with small but powerful daily habits like brushing and flossing your teeth twice a day. It’s never too late to start fresh!
Sharing Smiles, Not Bacteria
While the idea that cavities can be “contagious” might sound alarming, the real takeaway is that we have more control over our oral health than we realize. By taking simple preventative steps and encouraging good habits within your family, you can protect your pearly whites for years.
At London Little Bites Dentistry, we offer comprehensive dental services for all of your child’s dental needs. Book an appointment today!