How Often Should You Replace Your Toothbrush?

colorful toothbrushes — Never let your toothbrush get so old the bristles look as worn out as these. You're not doing your teeth any favors. Alexey Broslavets/Shutterstock

Replacing your toothbrush is one of the simplest tasks you can do to maintain good dental health, but many of us still don't do it as often as we should.

So how often should you replace yours? It depends on the type of toothbrush you use.

Replacing a Manual vs. Electric Toothbrush

If you brush with a manual toothbrush twice a day for 2 minutes as recommended, pretty much every dentist and the American Dental Association (ADA) say you need to replace your toothbrush every three to four months.

It's about the same for the head of a powered toothbrush, but it most likely needs swapping out at the 12-weeks mark. That's because electric toothbrushes often have shorter bristles that tend to wear down more quickly.

But what if you don't know when you bought your last toothbrush? Should you just replace it? Not necessarily. There are signs that indicate it's time for a change, whether you use a good old manual toothbrush or an electric.

Do a visual inspection of the bristles and look for signs of any of the following:

edges that are beginning to fray or bend
matting
overall bristle symmetry losing shape

Some toothbrushes have bristles that change color as they wear down, which provide an obvious visual signal that they need to be replaced.

If you use your toothbrush longer than recommended, the bristles will start to wear and fray, and they won't be as effective at removing debris and plaque. When too much plaque and food debris linger in your mouth, your risk of tooth decay and gum disease increases.

How to Make Your Toothbrush Last Longer

Here are a few things you can do to keep your toothbrush in good condition between replacements:

Always rinse your toothbrush after brushing to remove residual toothpaste and food debris.
Store your toothbrush in a place where it can't touch the head of another toothbrush and spread germs.
Store it upright and let it air dry. Never put it in a closed container while it's wet, as this creates an ideal environment for bacteria and mold to grow.
Never share toothbrushes, even with your closest loved ones.

Studies suggest toothbrushes can harbor bacteria — even fecal matter — so if you choose to clean yours, the ADA says to soak it in 3 percent hydrogen peroxide or Listerine mouthwash. That's because a 2010 study published in the Journal of Dentistry found that both methods reduce bacterial load by 85 percent.

You also can use a toothbrush sanitizing device, but look for one that is cleared by the U.S. Food and Drug Administration (FDA).

How to Maintain Good Oral Hygiene

If you're still using a manual brush, consider switching to a powered version. Electric toothbrushes have been proven to clean teeth and gums better than manual toothbrushes, promoting healthier gums and less tooth decay. It's likely because of the various movements they have that you don't get when using a manual brush (e.g., side-to-side, counter oscillation, rotation oscillation, circular).

So, on your next trip the neighborhood store, just grab a new toothbrush, and maybe make it an electric one. And of course, visit your dentist for checkups and cleanings on a regular basis. You'll probably leave with a free toothbrush to boot.