How do teeth "feel" the cold, sometimes to the point of causing unbearable pain? By asking this question, researchers have uncovered the role of a specific protein, a discovery that could lead to an effective treatment for those affected.

Why, can, the, cold, hurt, my, teeth?

Chewing or drinking something cold with a damaged or sensitive tooth can trigger a unique and particularly excruciating type of pain, but scientists have never fully understood how this pain signal is transmitted to the brain. Now, an international team of scientists has figured out how teeth feel cold and claim in the journal Science Advancesto have identified the molecular and cellular players involved. It turns out that in both mice and humans, dental cells called "odontoblasts" contain a cold-sensitive protein that detects temperature drops. Its name? TRPC5.

So the researchers say they have discovered a new function for odontoblasts, the cells that form dentin, the shell under the tooth enamel that envelops the soft dental pulp containing nerves and blood vessels. "We found that odontoblasts are also responsible for cold sensing," says Prof. Jochen Lennerz, one of the paper's lead authors and a member of Massachusetts General Hospital. "This study provides a new function for this cell, which is exciting from a scientific perspective. We now know how to interfere with this cold-sensing function to inhibit dental pain. "

Clove essential oil against dental pain

Their work focused primarily on ion channels, the pores in cell membranes that act as molecular gates. After detecting a signal, such as a chemical message or a change in temperature, the channels close or open, creating an electrical impulse that passes from cell to cell to the brain, heart and other tissues. After identifying the TRPC5 protein as a potential temperature sensor in experiments with mice, the scientific team discovered that those without the gene encoding TRPC5 did not respond to exposure of the teeth to cold in the usual way.

The researchers then confirmed the presence of the protein, which opens channels in the membrane of odontoblasts, in extracted human teeth that were cut into thin layers for microscopic study. "We have evidence that the TRCP5 temperature sensor transmits cold via the odontoblast and triggers nerve inflammation, creating pain and hypersensitivity to cold. This sensitivity may be the body's way of protecting a damaged tooth from further injury," adds Prof. Jochen Lennerz. This discovery also led them to identify a pharmacological target, which turned out to be a well-known home remedy.

This is clove oil, which has been used as a remedy for toothache for centuries due to its powerful analgesic properties. It contains an active agent, eugenol, which has the ability to block the action of the TRCP5 protein. Toothpastes containing eugenol are already on the market, but the researchers hope that the results of their study could lead to more powerful applications to treat teeth hypersensitive to cold. "There may be new applications for eugenol, such as systemic treatment of patients who suffer from extreme cold sensitivity due to chemotherapy," they conclude.