Toward a Society where Appropriate Oral Care Can Be Realized for Everyone, Anytime, Anywhere Activities for Creating Better Living Habits in Space


Lion has positioned “Creating Healthy Living Habits” as a top priority material issue to advance initiatives addressing Sustainability Material Issues in order to realize a sustainable society. Accordingly, we aim to provide opportunities for everyone to practice oral care at any time or place and have decided to approach this by focusing on oral care for people living in extreme environments, such as life in space. For example, water use restrictions on the International Space Station (ISS) are similar to conditions on Earth during times of disaster or severe water shortage. Thus, by working to develop products and services that transform tooth brushing in space into a more comfortable habit, we are contributing to the realization of a society where anyone, anywhere can appropriately practice oral care.
We promoted this theme under an in-house initiative that allows researchers to use up to 15% of their working hours on research topics of their own choosing. Such topics do not necessarily need to be directly related to their main job, rather, having this option gives researchers the opportunity to try out ideas. Researchers with similar ideas, even across departments, are also free to establish common research themes and work together.

Easy-Rinse Toothpaste Ideas

In space,*1 water is a very precious resource, and people need to be very conscious of this when engaging in such daily activities as washing their face or hair or brushing their teeth. As it is impractical to rinse out their mouths with water, once finished people typically swallow or spit the toothpaste out onto towels, resulting in discomfort and a feeling of residue in the mouth.*2
To solve this issue, Lion applied to the Japan Aerospace Exploration Agency’s project (JAXA) to answer their call for ideas and solutions themed on addressing challenges faced both by those living in space and on Earth and proposed an easy-rinse toothpaste.*3

Because this toothpaste is a foam rather than a conventional paste, it spreads easily across the teeth. Also, it is designed not to lather or leave a residue in the mouth. This toothpaste can thus simply be applied to a toothbrush and spat out with saliva after brushing the teeth. In addition, because unlike on Earth rinsing with water is not an option, we have ensured that the flavor does not remain in the mouth. One bottle of this toothpaste is enough for about five hundred toothbrushing sessions, making it is suitable for long-term use on the ISS for up to six months, ensuring comfortable toothbrushing habits. We also believe that this technology will contribute to cost reductions and compliance with resource limitations in future space development planning. Space exploration in the future is expected to involve living in space for even longer periods of time, and by making toothpaste easier to use, we will reduce mouth discomfort and provide better tooth brushing habits for life in space.
Our proposed toothpaste has been evaluated by JAXA as suitable for use on the ISS, and astronaut Koichi Wakata used it during his term on the ISS from October 2022 to March 2023.*4 Dr. Wakata commented that, “The foam texture of the toothpaste really feels like it reaches every corner of the mouth, and it’s easy to apply the foam to the toothbrush even in zero gravity. These kinds of products are a great help on the ISS where water is scarce.”*5

*1 Life on the International Space Station (ISS)
*2 Space Life Story Book published by JAXA (Japanese):
*3 JAXA calls for ideas to solve issues shared by those living in space and on Earth:
*4 JAXA report on shared issues and solutions for life both in space and on Earth:
*5 Excerpt from Dr. Wakata’s comments in “Daily Necessities in Space, an easy-rinse Toothpaste,” from the JAXA Digital Archives:

Summary and Future Outlook

We believe that this technology can be applied to situations other than space life, such as oral care in environments with scarce water resources such as during disasters on Earth, as well as in medical and nursing care settings. Going forward, based on the perspective of considering oral care appropriate for various environments during this initiative, we will advance research into providing oral care opportunities for even more environments and situations.

Related News Releases

1) Lion’s First Product Used on the ISS, Easy-Rinse Toothpaste Created by Our Researchers’ Independent Activities to Help Astronauts Live Better Daily Lives in Space (Japanese). 2) Lion’s Easy-Rinse Toothpaste Selected by JAXA for Potential Use as Daily Amenity on the ISS (Japanese).

R&D Case Study