Experimental microscopic robots that travel into tiny tunnels in teeth may one day offer lasting relief from tooth sensitivity, laboratory experiments suggest.

Tooth sensitivity - sharp, sudden pain triggered by hot, cold, sweet, or sour substances - occurs when the protective layers of the tooth are compromised, exposing the underlying nerve endings.

The researchers’ so-called CalBots are 400-nanometer magnetic particles loaded with a ceramic formula that mimics the natural environment of the tooth.

Guided by an external magnetic field, the tiny bots travel deep into the exposed tubules and assemble themselves into cement-like plugs that protect the nerve.

In lab experiments on extracted human teeth, high-resolution imaging confirmed that the bots had created tight seals, the researchers reported.

In animal tests, they found that mice with tooth sensitivity who had been avoiding cold water would drink it again after treatment with the CalBot solution.

Most current treatments for tooth sensitivity, such as desensitizing toothpastes, offer only surface-level relief and need to be reapplied regularly, while the CalBots would provide longer-lasting relief in just one application, the researchers reported in Advanced Science.

They hope their treatment – which still needs to be tested in humans – might eventually offer benefits beyond the relief of dental hypersensitivity, such as minimizing the penetration of bacteria into cavities and tooth injuries.

“We didn’t want to create a slightly better version of what’s already out there,” study leader Shanmukh Peddi, a post-doctoral researcher at the Indian Institute of Science in Bangalore, said in a statement.

“We wanted a technology that solves a real problem in a way that no one’s attempted before.”

Peddi is a co-founder of Theranautilus, a Bangalore nanotechnology and healthcare company.