Researchers use nanobots to eliminate bacteria in root canal

Iveta Ramonaite, Dental Tribune International

Mon. 23 May 2022

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BENGALURU, India: According to the American Association of Endodontists, approximately 25 million root canal treatments are performed annually, and over 90% of them are successful. To address treatment failure due to inadequate decontamination of the root canal system, researchers from the Indian Institute of Science and nanorobotics company Theranautilus have demonstrated that nano-sized robots can be effectively employed to kill bacteria in the dentinal tubules.

“The dentinal tubules are very small, and bacteria reside deep in the tissue. Current techniques are not efficient enough to go all the way inside and kill the bacteria,” Shanmukh Srinivas, a research associate at the Centre for Nano Science and Engineering (CeNSE) at the Indian Institute of Science and one of the co-founders of Theranautilus, said in a press release.

In the study, the researchers explored the potential of actively manoeuvred nanobots to disinfect dentinal tubules. Injected into extracted tooth samples, the nanobots were able to penetrate deep inside the dentinal tubules under the control of a device that generates a low-intensity magnetic field. By manipulating the magnetic field, the researchers were able to cause the surface of the nanobots to generate heat to kill bacteria nearby. “No other technology in the market can do this right now,” explained lead author Dr Debayan Dasgupta, a research associate at CeNSE and a co-founder of Theranautilus.

According to the findings, the nanobots were able to penetrate up to 2,000 μm into the dental tubules, thus achieving a vast improvement in penetration depth compared with ultrasonic and laser-activated irrigation. The researchers believe that using heat to kill bacteria is a safe alternative to using harsh chemical agents or antibiotics to decontaminate a root canal.

“We are very close to deploying this technology in a clinical setting, which was considered futuristic even three years ago,” co-author Dr Ambarish Ghosh, a professor at CeNSE, commented. “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,” he concluded.

To this end, the researchers are currently working on developing a novel medical device that can be easily placed inside the patient’s mouth and allows the dentist to inject and manipulate the nanobots inside the teeth during root canal therapy.

(a) Nanobots entering a dentinal tubule. (b & c) Schematic representation and electron microscope image of a nanobot moving through a dentinal tubule to reach a bacterial colony. (d & e) Locally induced heat from the nanobot killing bacteria. Live bacteria are green, and dead bacteria are red. (f) Band of targeted treatment done in human teeth. (Image: Theranautilus)

Researchers at Theranautilus, which was initially a laboratory spin-off from the institute, have previously demonstrated that magnetically controlled nanoparticles have the ability to trap and move objects using light, pass through blood and into living cells, and adhere firmly to cancer cells. After testing the dental nanobots in mice models, they deemed that the nanobots are safe to use in biological tissue.

The study, titled “Mobile nanobots for prevention of root canal treatment failure”, was published online on 28 April 2022 in Advanced Healthcare Materials, ahead of inclusion in an issue.

Editorial note:

Dental Triune South Asia had earlier covered the same research in August 2021. Click here to read