You bite into your favorite ice cream, and suddenly a wave of pain shoots through your teeth and straight into your brain. Has it happened to you? Do not worry, if eating ice cream or drinking cold drinks gives you that feeling, it means you suffer from cold-sensitive teeth.
Until a few months ago, the mechanisms behind this sensation were not fully understood, but recent research seems to have found the answer. While teeth can ache for a variety of different reasons, including tooth decay and gum erosion, the researchers in this study found that odontoblasts (cells found under tooth enamel) play a key role in the specific type of pain experienced by people with sensitivity to cold.
In mice and humans, odontoblasts contain cold-sensitive proteins that can detect a decrease in temperature through the use of an ion channel, known as TRPC5. In the study, the scientists found that TRPC5 was very sensitive to cold, but, at first, they could not determine where in the body this cold-sensing ability operated.
But this was only for a short period of time, since one day, while having lunch, they thought of the teeth as a part of the body that also feels cold.
Mice as study subjects
Thus, the team conducted a study in mice; some normal and others lacked TRPC5 or had their teeth immersed in a special solution. The researchers watched the mice’s neural activity as they applied an ice-cold solution to their teeth. In normal mice, neural activity was triggered after the cold solution touched their teeth, but the opposite was true in mice that lacked TRPC5 or those whose teeth were immersed in a solution to block the ion channel.
“We discovered that the odontoblasts, which support the shape of the tooth, are also responsible for detecting cold”, explained one of the team members, JochenLennerz, who added: “We now have definitive proof that the temperature sensor TRCP5 transmits cold through the odontoblasts and activates the nerves, creating pain and hypersensitivity to cold. This sensitivity may be the body’s way of protecting a damaged tooth from further injury”.
The team also noted that the study may help in the development of drug treatments, which target the cold sensor, to eliminate toothache and tooth sensitivity caused by low temperatures.