Scientists Have Created Microrobots That Can Automatically Brush and Floss Your Teeth

In a proof-of-concept study, University of Pennsylvania researchers showed that dental plaque and germs that cause tooth decay could be successfully treated and removed by a hands-free device.

In the future, a shape-changing robotic microswarm could replace the need for separate toothbrushes, rinses, and dental floss. The technology, developed by a multidisciplinary team at the University of Pennsylvania, may offer a fresh, automated way to do the daily tasks of brushing and flossing, which are tedious but crucial. This technique could be very beneficial for persons who lack the physical dexterity to effectively clean their teeth on their own.

Iron oxide nanoparticles with catalytic and magnetic characteristics make up these tiny robots. Using a magnetic field, scientists were able to manipulate their motion and design, producing either elongated threads that can slide between teeth like floss or bristle-like structures that remove dental plaque off the vast surfaces of teeth. In both instances, the release of antimicrobials by the nanoparticles, which destroy hazardous oral bacteria on the spot, is fueled by a catalytic process.

An infographic demonstrates how iron oxide nanoparticles are assembled into bristle- and floss-like structures while also exhibiting magnetic and catalytic capabilities. Credit: Penn Engineering/Melissa Pappas

The robotic assembly may adjust to a range of geometries to almost eradicate the sticky biofilms that cause cavities and gum disease, according to tests employing this technique on dummy and actual human teeth. In the journal ACS Nano, the Penn team published its findings demonstrating a proof-of-concept for the rob                  

According to Hyun (Michel) Koo, a professor in the Department of Orthodontics and divisions of Community Oral Health and Pediatric Dentistry at Penn's School of Dental Medicine and co-corresponding author on the study, "Routine oral care is cumbersome and can pose challenges for many people, especially those who have a hard time cleaning their teeth." It's a laborious, multi-step process where you first have to wash your teeth, then floss them, and finally rinse your mouth. The major breakthrough in this situation is the robotics system's ability to perform all three in a single, hands-free, automated manner.

According to co-corresponding author Edward Steager, a senior research scientist in Penn's School of Engineering and Applied Science, "Nanoparticles can be sculpted and controlled with magnetic fields in surprising ways." We create bristles that, like flossing, can expand, sweep, and even move back and forth across a space. It functions much like a robotic arm that can reach out and clean a surface. The device may be configured to automatically assemble nanoparticles and control motion.

The original "bristle-on-a-stick format" was enhanced by the use of electric motors, but the idea behind it remained the same. "This technology hasn't experienced any disruption in decades."

With the aid of this microrobotics technology, Penn researchers from the Center for Innovation & Precision Dentistry (CiPD), of which Koo is a co-director, began to take steps toward a significant disruption a number of years ago.

Their creativity resulted from a little luck. Iron oxide nanoparticles piqued the interest of research teams at Penn Dental Medicine and Penn Engineering, but for very different reasons. The catalytic activity of the nanoparticles captured the attention of Koo's team. They have the ability to activate hydrogen peroxide, releasing free radicals that can destroy germs that cause tooth decay and weaken dental plaque biofilms. Professor Kathleen Stebe, co-director of CiPD, Dean Vijay Kumar, and other engineering colleagues of Steager were investigating these nanoparticles as the basis for magnetically operated microrobots at the time.

The Penn collaborators combined the two applications in the current work with assistance from Penn Health Tech and the National Institute of Dental and Craniofacial Research. They built a platform to electromagnetically control the microrobots, enabling them to adopt various configurations and release antimicrobials locally to treat and clean teeth.

It will adapt to diverse surfaces whether you have straight teeth or crooked teeth, claims Koo. The device may be adjusted to fit into every crevice in the mouth cavity.

On a little piece of material that resembles teeth, the researchers optimized the movements of the microrobots. The effectiveness of the microrobots adapting to the intricate topography of the tooth surface, interdental surfaces, and gumline was then evaluated using 3D-printed tooth models created from scans of real human teeth obtained from a dental office. Last but not least, they tested the microrobots on actual human teeth installed in an oral cavity-like configuration.

The researchers discovered that the microrobotics system could successfully remove biofilms from these diverse surfaces, ridding them of all observable pathogens. Tests on the bristle formations on an animal model revealed that they did not affect the gum tissue, and the iron oxide nanoparticles have been FDA-approved for usage in other applications.

Using fluctuations in the magnetic field, the team's roboticists and engineers were able to precisely adjust the motions of the microrobots and regulate the stiffness and length of the bristles, proving that the system is totally programmable. The bristle tips might be made hard enough to eliminate biofilms yet soft enough to prevent harm to the gums, the researchers discovered.

According to the researchers, the system's adaptability might make it not only soft enough for therapeutic use but also individualized, able to adjust to each patient's particular oral cavity topographies.

The Penn team is looking at other ways to deliver the microrobots through mouth-fitting devices and is continuing to refine the robots' actions in order to take this technology to the clinic.

We have technology that, according to Koo, is just as effective as brushing and flossing your teeth without the need for manual skill. "We'd really like to see this benefit the elderly and those with disabilities. We think it will revolutionize present practices and significantly advance oral health care.

The National Institute of Dental and Craniofacial Research, Procter and Gamble, and Sungkyunkwan University all provided funding for the study.

By UNIVERSITY OF PENNSYLVANIA