A multi-disciplinary team of engineers, dentists, and biologists from the US have devised a microscopic robotic cleaning crew to precisely and non-invasively remove plaque from teeth.
With two types of robotic systems, one designed to work on surfaces and the other to operate inside confined spaces, University of Pennsylvania scientists—whose work is published in Science Robotics—showed that robots with catalytic activity can ably destroy biofilms, sticky amalgamations of bacteria enmeshed in a protective scaffolding.
Such robotic biofilm-removal systems could be valuable in a wide range of potential applications, from keeping water pipes and catheters clean to reducing the risk of tooth decay, endodontic infections, and implant contamination.
The team designed, optimised, and tested two types of robotic systems—called catalytic antimicrobial robots, or CARs—capable of degrading and removing biofilms.
The first involves suspending iron-oxide nanoparticles in a solution, which can then be directed by magnets to remove biofilms on a surface in a plow-like manner.
The second platform entails embedding the nanoparticles into gel molds in three-dimensional shapes. These were used to target and destroy biofilms clogging enclosed tubes.
Both types of CARs effectively killed bacteria, broke down the matrix that surrounds them, and removed the debris with high precision. After testing the robots on biofilms growing on either a flat glass surface or enclosed glass tubes, the researchers tried out a more clinically relevant application: removing biofilm from hard-to-reach parts of a human tooth.
The CARs were able to degrade and remove bacterial biofilms not just from a tooth surface but from one of the most difficult-to-access parts of a tooth, the isthmus, a narrow corridor between root canals where biofilms commonly grow.
“Existing treatments for biofilms are ineffective because they are incapable of simultaneously degrading the protective matrix, killing the embedded bacteria, and physically removing the biodegraded products,” team leader Hyun (Michael) Koo said.
“These robots can do all three at once very effectively, leaving no trace of biofilm whatsoever.”