Should I replace my toothbrush after being sick?

Closeup of blue toothbrush with toothpaste
Do I really need to replace my toothbrush after I’m sick? What’s the real risk?

Should you replace your toothbrush after you recover from sickness? Is it really necessary? Some people say that you should, others say that it doesn’t make a difference. Well, it turns out there are several ways to think about it.

First, you probably won’t get sick again from your toothbrush…

If you just had the flu, and brushed your teeth while sick, and continue using your toothbrush after you recover, it is extremely unlikely that you will get sick again from your toothbrush. There are several reasons why this is the case:

  1. Your body is already immune. Your immune system has already produced antibodies for that infection, so reinfection is very unlikely regardless of whether your toothbrush is carrying germs.
  2. The germs on your toothbrush have probably died already. When your toothbrush dries, most germs on it die. It’s really when your toothbrush remains wet that germs proliferate.

But if someone else stores their toothbrush close to yours…

If you keep your toothbrush in a container with other toothbrushes, then all of those toothbrushes should be replaced. Even if you aren’t at risk of being reinfected, other people could still get sick. Even though your toothbrush will dry and the germs on it will die, there’s still a good chance some germs will be transmitted to other toothbrushes, especially if they are used without being rinsed, or before drying out.

So, if you were sick with a particularly contagious infection (like the stomach flu), it’s best to err on the side of caution and replace everyone’s toothbrushes.

However, keep in mind, the risk of anyone getting sick is still very small. The ADA states that “there is insufficient clinical evidence to support that bacterial growth on toothbrushes will lead to specific adverse oral or systemic health effects.” They simply recommend “a common-sense approach,” especially for people who are higher risk for infections.

Our recommendation: just replace your toothbrush.

At the end of the day, our recommendation is to just replace your toothbrush. Why? Because a toothbrush is cheap, it’s probably overdue for replacement anyway (bristles wear out in 3-4 months), and it’s really not worth the effort to try to disinfect it.

Are there any things I can do that will make a difference?

Actually, yes. Here are a few things that the American Dental Association recommends:

  1. Don’t cover your toothbrush. This may seem counter-intuitive, but covers prevent your toothbrush from drying out. The longer your toothbrush remains wet, the easier it is for bacteria to stay alive and grow.
  2. Rinse your toothbrush thoroughly after using it. Rinsing your brush will effectively clean off any debris that may carry bacteria.
  3. Disinfect your toothbrush with hydrogen peroxide. A recent study showed that a 3% hydrogen peroxide solution was 100% effective in killing the bacteria on a toothbrush. So, if you’re worried about it, just soak your toothbrush for twenty minutes.
  4. Don’t store your toothbrush with other toothbrushes. For the reasons mentioned above, it’s best to keep them separated.
  5. Don’t share your toothbrush. This should go without saying, but just in case…