The practice of bartering probably began shortly after humans started communicating. "I'll draw a nice mural on your cave wall if you will let me sleep in it and eat some the animals you kill."
We've all heard stories from back in the days when doctors might accept produce or livestock from patients who had more product than money. But that was another era, and it's hard to picture in this day and time when some docs won't even give the time of day to person who isn't insured.
However, dental work seems to be one of those services subject to barter. (Probably has something to do with fewer insured patients, but that's a subject for another day.) Here's a dentist in New York who has offered to trade dental services for plumbing and tile work. The practice must be quite common as the IRS has provided a convenient reminder that a barter transaction is taxable. And the example they use, coincidentally enough, involves a dentist and plumber exchanging services.
Oh, by the way, in case you didn't know, I'll blog for food.