Stranger Than Fiction

When you go to the dentist for a checkup and cleaning, you likely expect at least some portion of your visit to involve the not-so-pleasant manual scraping with mechanical tools to remove sticky plaque from your teeth.

The very thought of having your teeth scraped may cause you to reschedule that upcoming appointment, but what if your dentist was able to deploy tiny robots to target and remove sticky plaque without scraping?

While that sounds like something straight out of a science fiction novel, it may soon be a reality.

A research team made up of dentists, engineers and biologists at the University of Pennsylvania have developed a microscopic robotic cleaning crew designed to clean plaque from the surfaces of the teeth. These robots can also reach the dental plaque that grows between the teeth and in confined, hard-to-reach areas.

Dr. Sean Endsley, a Waco, Texas, dentist, thinks the idea is exciting.

‘Removing sticky plaque from the teeth is one of the most important ways you can fight tooth decay and gum disease,’ Endsley said.

Plaque is a biofilm made up of bacteria that damage tooth enamel and cause inflammation in the gums. It is sticky but in many cases can be removed with regular and proper brushing and flossing.

The American Dental Association recommends that individuals brush at least twice per day and floss at least once per day to prevent bacterial buildup and biofilm overgrowth.

But, if proper oral hygiene isn’t a regular practice, this sticky film can be stubborn. Over time, it can harden into a material called calculus.

‘Calculus has to be physically removed from the teeth,’ Endsley said.

The scientists believe that the robots and other types of robotic biofilm-removal tools could be useful in a range of applications, from removing plaque and preventing tooth decay to keeping water pipes clean.

So, How Do They Work?

Working with engineers, the team was able to develop the robots and a way to control them using magnets. The significant benefit to this approach was that it allowed the robots to be tether-free.

Two types of robotic systems came out of the project and were dubbed catalytic antimicrobial robots, or CARs. Both systems could degrade and remove biofilms.

The first group used suspend iron-oxide nanoparticles, which can be managed by magnets to degrade and remove biofilms on surfaces.

The second group was designed to be embedded into gel molds to break down bacteria in hard-to-reach spaces – like between teeth and in pipes.

Both types of CARs work effectively to kill bacteria and remove bacterial debris.

The team behind the tooth-cleaning robots also envisions their product being able to help eradicate bacteria – particularly bacteria that are antibiotic-resistant. This benefit is one of increasing importance as more and more bacteria are adapting themselves to survive against antibiotics.

This isn’t the first time the Penn researchers have gotten creative in battling bacteria; previous work resulted in outside-the-box methods to break down biofilm such as using iron-oxide-containing nanoparticles to work as a catalyst to activate hydrogen peroxide to kill bacteria.

Source: University of Pennsylvania. ‘An army of micro-robots can wipe out dental plaque.’ ScienceDaily. ScienceDaily, 25 April 2019.