Have you ever heard that you should replace your toothbrush after you are sick?  I had heard that you should, but I never understood why.  After you get sick, your body figures out how to fight the illness and then makes you healthy again.

Once your body knows how to fight off the illness, you usually won’t ever get that exact same illness again.  Because of this, I wondered why some people recommend changing your toothbrush after you get sick.

The Case For Replacing Your Toothbrush After You’ve Been Sick

The book Primary Preventive Dentistry says, “In addition to regular [toothbrush] replacement, replacement after contagious illness is imperative.”

…and that’s all.

The authors don’t say why you should replace your toothbrush after you get sick, and they don’t even bother to cite any studies that support their recommendation.

Colgate mentions on their oral health care website that you should replace your toothbrush after you’ve been sick:

It is also important to change toothbrushes after you’ve had a cold, the flu, a mouth infection or a sore throat. That’s because germs can hide in toothbrush bristles and lead to reinfection.

Again, they don’t give any references.  Let’s look more closely at the case against replacing your toothbrush after you’ve been sick to determine the strength of their argument.

The Case Against Replacing Your Toothbrush After You’ve Been Sick

Now don’t get too excited, but the American Dental Association has a whole page dedicated to their policy on toothbrush care — don’t worry, I read it so that you don’t have to!

The ADA never states on that page that you should replace your toothbrush after you get sick.  In fact, they even acknowledge that bacteria is almost always on your toothbrush and that your toothbrush can even be contaminated before you buy it because toothbrushes aren’t required to be sold in sterile packaging.

Ultimately, the ADA has this to say:

Although studies have shown that various microorganisms can grow on toothbrushes after use, and other studies have examined various methods to reduce the level of these bacteria, there is insufficient clinical evidence to support that bacterial growth on toothbrushes will lead to specific adverse oral or systemic health effects.

Basically, the ADA is at a loss when it comes to finding evidence linking bacteria on your toothbrush to any bad health effects.

About a year ago, I asked one of the dentists at my school what she thought about changing your toothbrush after you’re sick.  She told me that there is no scientific evidence that says that you should.  She also brought up the point that it would be hard to know exactly when to change your toothbrush since you can’t really tell when you’re very first infected and when your body has finally eliminated all of the bacteria/virus that caused the illness.

Conclusion

Although I don’t think it’s necessary to change your toothbrush after you get sick, I do believe that it’s a good idea to replace your toothbrush every 3 to 4 months because your brush can become a nice home for all of the bacteria that live in your mouth.  There may be exceptions if you have a compromised immune system or if you have other health issues that affect your ability to fight off infection.

What are your thoughts? Do you replace your toothbrush after you’re sick?  I’d love to hear about your views in the comments section below!