Dentists prescribe 10 percent of all antibiotics in the US - one of the highest rates of any medical specialism. In other words, they prescribe 26.6 million of the 266 million courses of antibiotics dispensed each year.
But according to a new study, 80 percent of those (roughly 21.3 million prescriptions) are unnecessary, mostly in the Western US.
The study by Chicago researchers is the first attempt to gauge nationally how and where dentists are prescribing these drugs, to pinpoint where we could cut down.
The more antibiotics we take, the faster we will all become resistant to the life-saving drugs. Despite global efforts to curb antibiotic use, little has changed in the last few decades, but few studies have dug into why.
One obvious area to target was the practice of prescribing antibiotics before a dental visit - known as antibiotic prophylaxis - for people with high risk of infection from prosthetic joints or heart conditions.
But research has suggested it may not be necessary or effective, so new US dentistry rules published in 2007, and tightened again in 2013, said only people with the highest risk should get pre-appointment pills.