Are Cavities Contagious?

Dental cavities are pretty standard—almost everyone has a few as a kid—but did you know that they can be contagious? That’s right, you can catch a cavity! However, there is no need to worry: we’re here to answer your questions about everything you need to know when it comes to cavities. 

Where Do Cavities Come From?

Now that you know cavities can be contagious, you might be wondering how they form in the first place. 

As a tooth decays, cavity-causing bacteria releases acids that break down tooth enamel; then it spreads to the dentin, where blood vessels are. That’s how cavities initially form, but if the cavity-causing bacteria can get a hold of sugars and other acids, it can cause more severe damage such as destroying a tooth or creating even larger cavities. 

How Do Cavities Spread?

Cavities spread through the exchange of cavity-causing bacteria in saliva, like when you kiss someone, share a drink, or share a toothbrush; you are essentially swapping whatever bacteria is in your saliva with the bacteria in someone else’s. 

From Toothbrush to Toothbrush

Blood and plaque can quickly build up on your damp toothbrush, which is precisely the kind of environment that cavity-causing bacteria thrives in. If your loved one has a cavity and you use the toothbrush that the bacteria has been on, then you run the risk of exposing your pearly whites to cavities, too. You might also want to ensure that your toothbrushes are kept separate; storing damp toothbrushes together on your bathroom counter creates a bacteria breeding ground!


If sharing a toothbrush can help cavity-causing bacteria travel from one mouth to another from the saliva on toothbrushes, then kissing is on the next level of saliva swapping. What a romantic way to think about it, right? Kissing a partner with poor oral hygiene (on their way to tooth decay) is a one-way ticket to cavity town! 

Plates, Cups, Cutlery, Oh My!

Sure, kissing and sharing toothbrushes seem like obvious ways to spread dental cavities around, but have you considered the risk you take when sharing a drink? Just like sharing a toothbrush, sharing your cups or dining utensils can transfer cavity-causing bacteria through the trace amounts of saliva you leave behind on them before washing. 

Here’s How to Get to the Root of Your Cavity Problem:

#1: Brush and floss regularly. Use your own toothbrush and floss to do your best to brush away debris that could potentially harbor cavity-causing bacteria, such as food particles or plaque. It’s particularly important to give your teeth and gums an extra-thorough clean if you have a sweet tooth, since cavity-causing bacteria are pretty fond of sugar

#2: Schedule routine cleanings and exams with your dentist. Maintaining scheduled appointments with your dentist can help you to do the very best to keep your oral hygiene in the best shape possible. Not only can your dentist make your teeth sparkle, but they can also find the root of your problem and assist you if you think you may have a cavity. 

It’s best to schedule a dental exam every year to guarantee that your dentist can spot a cavity一or another dental concern一before a tooth is excessively damaged. If you want to experience the best care for your oral health, contact us to schedule a check-up and cleaning at LeCroy Dental!