How Do Astronauts Brush Their Teeth?

With the 50th anniversary of the Apollo 11 mission, the country has once again turned its eyes to space.

The thought of space travel is still mysterious and bizarre to most of us stuck here on earth. Though, through the use of the International Space Station, men and women are now staying in space for months—and even more than a year—at a time, and videos and photos sent back to Earth are giving us all a look.

[youtube https://www.youtube.com/watch?v=1lec-tv0uY8]

Astronauts also talk about daily life, and the lack of gravity and orbiting thousands of miles above earth is no excuse to abdicate hygiene—including oral hygiene. Plaque buildup does not take a break when you’re in space.

However, in case you hadn’t yet stopped to think…without gravity, using traditional toothpaste is nearly impossible to use in space. This NASA video highlights how astronauts brush their teeth in space and the unique circumstance they must overcome.

Strong teeth and gums in space

Before heading to space, it’s important to go in with strong teeth and gums. While astronauts do lose bone density due to the zero gravity in space, they don’t lose enough density to significantly affect their jaws.

The real danger to the teeth and jaw is velocity. Astronauts experience extreme conditions during launch and landing. Traveling at G-force speeds creates extreme pressure in the oral cavity, so having healthy teeth at the start makes a dramatic difference. Strong teeth and gums are essential to help the body more easily absorb intensive shocks.

In addition to the G-forces, teeth are put under a significant amount of pressure. During launches, astronauts are exposed to forces that are up to four times their own body weight. If an astronaut has not taken good care of his or her teeth, cavities could potentially loosen and fall out. The same pressure applies on re-entry as well. Astronauts travel at a rate of about 6.2 miles per second.

Brushing your teeth in space

We know how important water is to brushing your teeth, so how do astronauts accomplish that when there are no faucets on a spaceship?

Or what about caps on the toothpaste? Have you ever lost one in your bathroom? While it might have slipped under the counter, at least you don’t have to worry about it floating away!

To solve these problems, NASA invented toothpaste without detachable caps. Viola, no more lost lids! For water, astronauts use a drink bag that is closed with a straw clamp. Astronauts pop off the clamp and squeeze out beads of water onto the toothbrush, which get sucked into the bristles. Then you can brush your teeth as normally as possible.

At the end of this routine daily task, you’re used to spitting out excess toothpaste, right? But once again, in space there isn’t a sink, and if you spit it out it would all just float around. When asked, astronauts admit to just swallowing the toothpaste because it was the most efficient way to dispose of it.

Next time you brush your teeth in the comfort of your bathroom—and in our Earthly gravity—think of the astronauts who are in space brushing their teeth as well! Send a wave up to the space station, and swish with relish.