How do astronauts brush their teeth?

Last week we watched the historic launch of the Artemis II. As I watched this with my staff in the comfort of our office here is Darien, CT, I had to ask - how are these astronauts going to brush their teeth up there for the next ten days? I was surprised to find out that dental health is very important to NASA and the astronauts, and their dental care starts way before take off.

Yes, astronauts undergo rigorous dental screenings and comprehensive check-ups before spaceflight to ensure they have excellent oral health. This prevents emergencies—such as broken fillings or infections—caused by high G-forces during launch, atmospheric pressure changes, and the lack of professional care in space. Astronauts are classified into groups based on oral health (Class I, II, or III), with those needing immediate dental treatment often grounded, as a toothache can require an early, costly return to Earth.

• High-G forces and intense vibrations during liftoff can dislodge loose fillings, crowns, or bridges. There are special space environment issues too: Microgravity causes fluid shifts, causing "dry mouth" which increases decay risk, while long-term exposure can lead to reduced bone density affecting the jaw. Sometimes, astronauts opt for or are advised to have wisdom teeth removed before long missions. While all care is taken to avoid issues, crews are trained in emergency procedures like temporary fillings or tooth extraction.

Once there are in flight, the routine dental care is not so routine.

In order to avoid problems with waste, NASA developed foamless, ingestible toothpaste called NASAdent. Research comparing NASAdent to commercially available toothpastes showed comparable cleaning ability and user acceptance. Astronauts can use standard issue toothpaste, but many use toothpaste of the edible variety to reduce water consumption.

Astronauts brush their teeth in space much like on Earth, but with specialized techniques to manage zero gravity, such as swallowing instead of spitting. They use standard, soft-bristled toothbrushes and toothpaste, often wetting the brush with water from a pouch and swallowing the foam to prevent liquid from floating away. 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.