Scientists conducting oral health research in space

Iveta Ramonaite, Dental Tribune International

Tue. 15. June 2021

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NEW YORK, U.S.: As the saying goes, the sky is the limit. This is true for the scientists conducting the first oral health experiment in space to investigate the growth and response of oral bacteria to treatment agents in zero gravity. The project, which is being sponsored by the International Space Station U.S. National Laboratory and conducted in collaboration with NASA and Colgate-Palmolive, will last two months and is partly aimed at improving oral health treatment on the ground.

For the experiment, engineers from the University of Nevada, Las Vegas (UNLV) have designed novel 3D-printed microfluidic pump devices that operate automatically. On June 3, these devices were sent to the space station in 25 kits that include the saliva and bacteria collected from 30 UNLV dental clinic patients. The bacteria consist of those found in a healthy oral environment and those that cause dental caries and periodontal disease.

In space, the researchers will grow the oral bacteria on 5 mm hydroxyapatite chips in the pump devices at 37 °C, the typical human body temperature. The devices will continuously dispense the liquid nutrients that are responsible for bacterial growth over the chips at an extremely low flow rate to mimic conditions in the mouth, and each test will run for 48 hours.

“There are many great oral hygiene products. But if you think about long-term space travel, there’s no guarantee that the Earth methods will work in zero gravity,” project collaborator Prof. Jeffrey Ebersole, associate dean for research at UNLV School of Dental Medicine, said in a press release. “This experiment will help push the envelope on understanding how one deals with oral health—both maintaining quality oral care and treating diseases—in space.”

After approximately two months, the kits will be sent back to Earth aboard the SpaceX Dragon spacecraft and the researchers will examine the effects of the microgravity environment on the oral bacteria and the effectiveness of the bacteria-fighting agents found in Colgate-Palmolive oral health products against the metabolization of nutrients and the formation of biofilms in space. The data from the bacteria grown on board the space station will then be compared with the data extracted on the basis of similar bacteria grown on the ground.

A multichannel microfluidic device developed by researchers from the University of Nevada, Las Vegas. (Image: Shengjie Zhai/University of Nevada, Las Vegas)

Commenting on the announcement, Chief Technology Officer at Colgate-Palmolive Dr. Patricia Verduin said in a press release: “Colgate’s purpose is to reimagine a healthier future for all people, their pets and the planet. We constantly strive to push the limits of research and development—and now we’re pushing even further, into space.”

Needless to say, the project has caused great excitement among its collaborators and has even helped to fulfill some lifelong dreams. “Along with firefighter and dinosaur hunter, astronaut seems to be on every child’s list of dream jobs,” commented project collaborator Dr. Shengjie (Patrick) Zhai, a research scientist in the Department of Mechanical Engineering at the university. “Now, my astronaut dream has come true in another way.”

Once the project has been completed, the researchers will use the data to find novel ways to tackle oral health disease and to develop improved dental health therapies on Earth. “Our unique partnership with ISS National [Laboratory] and [UNLV] will help us go beyond what’s expected, beyond what’s known and even beyond our planet to test and accelerate the science of oral health,” Verduin concluded.

Editorial note: This is the first of several research projects planned to be conducted in space by Colgate-Palmolive and ISS National Laboratory. The project was initiated in 2019, but had to be put on hold owing to the COVID-19 pandemic.