WHEN astronauts leave Earth, they take more than courage and advanced technology with them — they also take their toothbrushes.
Oral health might seem like a small concern compared to rocket science and spacewalks, but keeping teeth and gums healthy is essential for astronauts living and working in space for weeks or even months at a time.
A dental problem in orbit isn’t just uncomfortable; it can threaten mission success when immediate professional care is millions of miles away.
Before ever reaching space, astronauts undergo rigorous dental screening. Any cavities, gum disease, or questionable dental work is treated well in advance.
Wisdom teeth are often removed proactively to eliminate the risk of infection later. The goal is simple: minimize the chance of dental emergencies during a mission.
Daily oral hygiene in space looks familiar — but with a few key differences. Astronauts brush their teeth twice a day using standard toothbrushes and toothpaste. However, there’s a twist: in microgravity, you can’t simply spit into a sink. Instead, astronauts either swallow the toothpaste foam or spit it into a towel, which is later sealed and disposed of.
Toothpaste used in space is safe to swallow in small amounts, making this process practical and safe.
Flossing is also part of the routine, though it requires extra care. In microgravity, tiny droplets and particles float away instead of falling downward. Astronauts floss slowly and deliberately to prevent debris from drifting into equipment or air vents. Some astronauts prefer disposable floss picks, which are easier to control in weightlessness.
Hydration plays an important role in oral health as well. Saliva helps protect teeth by neutralizing acids and washing away bacteria. In space, bodily fluids shift toward the head due to microgravity, which can affect saliva flow and cause a sensation similar to nasal congestion. Astronauts are encouraged to drink enough fluids to support overall and oral health, even when they don’t feel thirsty.
Diet is another factor. Space food is carefully designed to reduce crumbs and stickiness, which helps protect both spacecraft systems and teeth.
However, many space foods are processed and may contain sugars or carbohydrates that contribute to plaque buildup. This makes consistent oral hygiene even more important. Chewing sugar-free gum is sometimes used to stimulate saliva and help clean teeth between meals.
For longer missions, astronauts receive basic medical and dental training. They learn how to manage minor dental issues, such as temporary fillings or gum irritation, using onboard medical kits. Ground-based flight surgeons and dentists can guide astronauts through procedures via real-time communication if needed.
As space agencies plan missions to the Moon, Mars, and beyond, oral health is becoming an even bigger priority. Researchers are studying how microgravity affects bone density in the jaw and the long-term health of teeth and gums. These insights not only protect astronauts but may also improve dental care on Earth.
In space, there’s no dentist down the street—but with preparation, discipline, and a floating toothbrush, astronauts manage to keep their smiles mission-ready
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Dr. Joseph D. Lim, Ed. D., is the former Associate Dean of the College of Dentistry, University of the East; former Dean, College of Dentistry, National University; Past President and Honorary Fellow of the Asian Oral Implant Academy; Honorary Fellow of the Japan College of Oral Implantologists; Honorary Life Member of the Thai Association of Dental Implantology; and Founding Chairman of the Philippine College of Oral Implantologists. For questions on dental health, e-mail jdlim2008@gmail.com or text 0917-8591515.
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Dr. Kenneth Lester Lim, BS-MMG, DDM, MSc-OI, graduated Doctor of Dental Medicine, University of the Philippines, College of Dentistry, Manila, 2011; Bachelor of Science in Marketing Management, De la Salle University, Manila, 2002; and Master of Science (MSc.) in Oral Implantology, Goethe University, Frankfurt, Germany, 2019. He is an Associate Professor; Fellow, International Congress of Oral Implantologists; and Fellow, Philippine College of Oral Implantologists. For questions on dental health, e-mail limdentalcenter@gmail.com./PN
