Your Toothbrush is Home to 10 Million Bacteria

The old Latin idiom “Who will guard the guards?” typically raises questions about accountability and power. But there’s an oral health interpretation of that age-old riddle that might read something like, “Who will brush the brushers?”

Believe it or not but your toothbrush and toothbrush holder might be some of the dirtiest items in your bathroom. In fact, they could even have more bacteria than your toilet seat.

While philosophers like Plato and Descartes might still be banging their heads against the wall—or the coffin—trying to find a way to watch the watchers, dentists have long since figured out how to floss the flossers.

Exactly How Dirty is Your Toothbrush?

The answer to the question, “How dirty is my toothbrush?” is a little complicated. On the one hand, your toothbrush is far dirtier than you might like to know. On other hand, it’s a lot cleaner than you might expect.

According to researchers at the University of Manchester in the UK, the average toothbrush is home to 10 million bacteria. While that number comes with a certain amount of teeth-shattering awe, it’s worth noting that most of those bacteria are perfectly harmless. In fact, most of them would have originated in your mouth in the first place. But not all of them.

Every time you flush the toilet, you send a flurry of bacteria into the air. Those airborne bacteria, including E. coli, will eventually come floating back down and can contaminate your toothbrush. Similarly, bacteria from your shower can roam to the other areas of your bathroom, including countertops, and increase the chances of cross-contaminating your toothbrush.

How to Clean and Disinfect Your Toothbrush

Toothbrushes are supposed to clean your teeth, not make them dirtier. Fortunately, dentists have come up with a few ways to make our bristle-headed friends much, much more sanitary. Learn how to clean your toothbrush for a brighter—less bacterial—smile.

  1. Hot Water

It’s an old trick but an effective one. Bring a pot of water to a rolling boil and then soak your toothbrush in the water for approximately 3 minutes. Boiling water is hot enough to kill most bacteria found on your toothbrush. It’s also hot enough to damage your toothbrush so inspect it after cleaning it.

  1. Hydrogen Peroxide

Hydrogen peroxide is a potent antiseptic with the power to whiten your smile and clean your toothbrush. Like boiling water, you’ll want to soak your toothbrush in a diluted solution of hydrogen peroxide and water for approximately 3 minutes. Over time and repeated use, hydrogen peroxide can degrade the plastic coating of your toothbrush so be careful when inspecting it.

  1. Antibacterial Mouthwash

What’s good for your mouth is good for your toothbrush—excluding fluoride gum. Soak your toothbrush in a capful of mouthwash once a week to kill the bacteria that have decided to live where they aren’t welcome. Over-the-counter mouthwash shouldn’t degrade your toothbrush quite like hot water or hydrogen peroxide so you can let it soak for as long as 15 minutes.

  1. Toothbrush Sanitizer

Bacteria don’t particularly care for ultraviolet light. In fact, UV does the same thing to bacteria that it does to vampires—the scary kind, not the sparkle-in-the-sun kind. Toothbrush sanitizers are devices that use ultraviolet light to disinfect your toothbrush so that you can bask in the radiance of your own smile. There are tons of different options on the market so you’ll just have to select whichever toothbrush sanitizer best suits your needs.

  1. Replace Your Toothbrush

Even if you boiled your toothbrush in a hydrogen peroxide solution before soaking it in mouthwash and air drying it on the beach, there would still be some bacteria on your brush. Not to mention, your toothbrush would probably be a hunk of misshapen plastic. Eventually, the time will come for you to replace your toothbrush. The American Centre for Disease Control and Prevention (CDC) advises replacing your toothbrush every 3 to 4 months but that number can vary based on your brushing habits.


Whichever way you choose to clean and disinfect your toothbrush, there is one way to ensure that your toothbrush stayer cleaner for longer. Storing your toothbrush in a covered space within your washroom such as within a case or a cupboard can reduce the chances of cross-contamination. Nevertheless, bacteria love dark places to grow so regular cleaning and replacing is something of an inevitability.

Talk to Your Dentist

If anyone knows a thing or two about keeping dental tools clean, it would be your dentist. Dawson Dental has over 30 state-of-the-art dental offices across southern Ontario. Book your next appointment with us today and get the brighter, perfectly-sanitized smile that you deserve.