A team of researchers from Boston University have discovered a new action for odontoblasts, the dentin-forming cells, the shell under the tooth’s enamel that surrounds the soft tooth pulp containing nerves and vessels blood. The results of the study were published in the journal Science Advances.
“We found that odontoblasts, which support the shape of the tooth, are also responsible for feeling cold,” says pathologist Jochen Lennerz, MD, PhD, one of the paper’s lead authors and medical director of the Center for Integrated Diagnostics at Massachusetts General Hospital (MGH). “This research adds a new function to this cell, which is inspiring from a basic science perspective. But now we know how to block this cold sensory action to prevent dental pain. . “
Teeth that are injured from exposure to cold can occur for many reasons. Many people have experienced severe pain from a cold when they have a hole in a tooth from an untreated cavity, for example. But teeth can also be very sensitive to colds from gum erosion as a result of aging. Some cancer patients treated with platinum-based chemotherapies have a cold sensitivity all over their bodies. “Wind on the face records as a real pain in the teeth, which can even cause some patients to stop treatment,” Lennerz says.
Examining tooth pain is extremely difficult. Tooth hardness makes it a challenging material to diagnose and induce tooth pain in people the tooth needs to be opened. The team of researchers therefore performed experiments on mice with molars drilled under anesthesia. Mice with dental injuries show pain with their behavior; they drink up to 300 percent more sugary water than their uninjured toothpaste, for example. In a previous study, the team of researchers had discovered TRCP5, a protein encoded by the TRCP5 gene that is expressed in nerves in many parts of the body. Their previous discovery allowed the researchers to zero in on TRCP5 as a mediator of pain from a cold.
By examining genetically modified mice lacking the TRCP5 gene, the researchers found that the mice with injured teeth did not show the growing drinking behavior and behaved like uninjured mice dentistry.
“We now have conclusive proof that the TRCP5 temperature sensor transmits cold through the odontoblast and stimulates nerves to fire, creating cold pain and hypersensitivity,” Lennerz says. “This cold sensitivity may be the body’s way to protect a damaged tooth from further injury.”
Specifically, in response to cold, the TRCP5 protein opens channels in the membrane of odontoblasts, enabling other molecules, such as calcium, to enter and interact with the cell. If the crush of the tooth is pulled out of a deep cavity, for example, TRCP5 is unstable, causing more electrical signals through the nerves protruding from the root of the tooth and running to the brain, where see pain. As gums leak from aging, teeth can become insensitive because the odontoblasts feel cold in an area exposed to the tooth. “Most cells and tissues slow down their metabolism in the presence of a cold, which is why donor organs are put on ice,” Lennerz says. “But TRPC5 makes cells more active in cold, and the ability of odontoblasts to feel cold through TRPC5 makes this discovery so encouraging.”
Lennerz confirmed the presence of the TRPCS protein in extracted human teeth, which was a tour de technical force. “Our teeth are not intended to be cut into ultra-thin layers until they are examined under the microscope,” says Lennerz, who had to decontaminate the teeth and place them in epoxy resin before applying. they slice on them and mark the TRPC5 channels into the odontoblasts.
The research team identified a medication target for reducing tooth sensitivity to colds. For centuries, cloves oil has been used as a remedy for tooth pain. Eugenol is the active agent in cloves oil, which occurs to inhibit TRCP5. Toothpaste containing eugenol is already on the market, but the findings of this study could lead to more powerful applications to treat teeth that are hypersensitive to cold. And there may be modern applications for eugenol, such as routinely treating patients for extreme cold sensitivity from chemotherapy. “I’m excited to see how other researchers apply our findings,” Lennerz said.
