Since the late 19th century, dentists have been using local anesthesia to make us more comfortable. These days, few people would even think of having a dental procedure like porcelain veneers or preparation for a dental crown without anesthetic, but it seems we still don’t quite understand how dental anesthesia works. New research has exposed a crucial mechanism in the function of dental pain relief.
Scanning the Brain for Pain
Researchers at the University of Zurich attempted to determine the mechanism of dental pain relief by looking at the brains of patients who were given anesthesia. The study involved 28 men with an average age of 27 who had functional magnetic resonance imaging (fMRI) of their brain. While the men were being scanned, they were also being subjected to electrical shock of a tooth (similar to an electric pulp tester) that created a pain sensation that the subjects rated as a 5 on the typical 0-10 scale.
After a five-minute stimulation and scan without an injection, patients were given an injection, either of anesthetic or placebo, and then scanned again. Those who were given anesthesia experienced pain relief an average of 4.5 minutes later, while those that got a placebo didn’t experience any pain relief for the entire 16 minutes of the second phase.
What researchers found was that dental pain in the placebo group was accompanied by activation in the posterior insula, where pain is typically registered and evaluated. However, in the group that got anesthesia, active connections were made with the midbrain, which seemed to correspond to pain relief.
Researchers suggest that this means dental pain has its own special brain regions governing both its experience and its relief.
What this research may yield in the future is an approach to dental pain that doesn’t rely on anesthesia at all. Instead, we might stimulate the proper brain areas to avoid dental pain.
In the meantime, though, we have other tools that can help us improve your comfort during dental procedures. Sedation dentistry helps if you have anxiety that makes it harder for you to get numb.