No Waste. Since there's no good way to dispose of waste in space, astronauts use lots of chewable and edible products to clean their teeth. Everything has to be ingestible, because there's no regular garbage. Instead of spitting out their toothpaste, astronauts swallow it, because there's nowhere for the spit to go!

Is it OK to swallow toothpaste in space?

The toothpaste astronauts use can be swallowed after brushing (edible toothpaste) and the mouth is then cleaned with a wet wipe. The astronauts have to brush with their mouth as closed as possible to prevent the toothpaste floating out!

Do astronauts use regular toothpaste?

Today, astronauts use traditional toothpaste and toothbrushes to maintain excellent dental health as demonstrated by Col. Chris Hadfield while he was a commander of the International Space Station.