Biofilm can form on surfaces of all kinds, including biological surfaces, like that of a tooth, or joint surfaces, or surfaces of objects, like implants, catheters or water pipes.
Difficult to remove, biofilms contain a sticky matrix that holds the bacteria and protects them from antimicrobial agents.
A team of biologists, dentists, and engineers from the University of Pennsylvania have developed two kinds of robots to clean dental plaque. The first works on surfaces and the second inside confined spaces. These are robots with the catalytic ability to disintegrate biofilms and sticky bacteria hiding in protective scaffolding. These robots, called Catalytic Antimicrobial Robots, or CARs, are capable of degrading and removing biofilms.
The two groups are divided as follows: The first type suspends iron-oxide nanoparticles in a solution, which are then directed by magnets to remove biofilms formed on the tooth surface, in a plow-like manner. The second category of robots involves fixing the nanoparticles in gel molds in 3D shapes. These then target and destroy biofilms clogging enclosed tubes.
Both types of micro-robots effectively kill bacteria, break down the matrix that is around them, and remove debris with high precision.
The researchers have tried out CARs on a more clinically relevant place: Biofilm removal from hard-to-access parts of a human tooth.
The microscopic robots were able to remove and disintegrate bacterial biofilms from the tooth surface, especially from a difficult-to-reach part of a tooth: the isthmus, a narrow corridor between root canals where biofilms commonly grow.
The leader of the study remarked that existing treatments for biofilms are somewhat ineffective because they do not simultaneously degrade the protective matrix, kill the attached bacteria, and remove the biodegraded products.
CARs can do all three of these at once and very effectively. With the plowing-away action of these microscopic robots, the degraded debris of the biofilm and the chance of it re-growing lowers significantly. Usually, the treatment of biofilms that form on teeth requires manual labor. With the introduction of this microscopic cleaning crew, new treatment options will become available.