IISc scientists develop tiny robots that can deep clean teeth using a magnetic field

Nano-sized robots manipulated using a magnetic field can help kill bacteria deep inside teeth, and boost success of root canal treatments, according to a study by researchers at Indian Institute of Science (IISc) Bengaluru.

Root canal treatments are routinely carried out to treat tooth infections in millions of patients. procedure involves removing infected soft tissue inside tooth, called pulp, and flushing tooth with antibiotics or chemicals to kill bacteria that cause infection.

However, many times, treatment fails to completely remove all bacteria -- especially antibiotic-resistant bacteria such as Enterococcus faecalis -- which remain hidden inside microscopic canals in tooth called dentinal tubules.

" dentinal tubules are very small, and bacteria reside deep in tissue. Current techniques are not efficient enough to go all way inside and kill bacteria," said Shanmukh Srinivas, Research Associate at Centre for Nano Science and Engineering (CeNSE), and co-founder of IISc-incubated startup, ranautilus.

In study published in journal vanced Healthcare Materials, researchers designed helical nanobots me of silicon dioxide coated with iron, which can be controlled using a device that generates a low-intensity magnetic field.

se nanobots were n injected into extracted tooth samples and ir movement was tracked using a microscope.

By tweaking frequency of magnetic field, researchers were able to make nanobots move at will, and penetrate deep inside dentinal tubules.

"We have also established that we can retrieve m we can pull m back out of patient's teeth, said Srinivas.

"Crucially, team was able to manipulate magnetic field to make surface of nanobots generate heat, which can kill bacteria nearby. No or technology in market can do this right now," said Debayan Dasgupta, Research Associate at CeNSE, and anor co-founder of ranautilus.

Previously, scientists have used ultrasound or laser pulses to create shockwaves in fluid used to flush out bacteria and tissue debris, in order to improve efficiency of root canal treatment.

However, se pulses can only penetrate up to a distance of 800 micrometers, and ir energy dissipates fast. nanobots were able to penetrate much furr -- up to 2,000 micrometers.

Using heat to kill bacteria also provides a safer alternative to harsh chemicals or antibiotics, researchers said.

y tested dental nanobots in mice models and found m to be safe and effective.

researchers are also working on developing a new kind of medical device that can easily fit inside mouth, and allow dentist to inject and manipulate nanobots inside teeth during root canal treatment.

"We are very close to deploying this technology in a clinical setting, which was considered futuristic even three years ago. It is a joy to see how a simple scientific curiosity is shaping into a medical intervention that can impact millions of people in India alone, Ambarish Ghosh, Professor at CeNSE ded.