At least it isn't a request for trade with a plastic surgeon, a gynecologist or a chiropodist.
I have seen ladies offer trades for trades work, there have been some that did full renos on their houses from their backs. I have to say I have had more than one barter encounter once I got to know the provider.
Just have to wonder, sometimes, whether you want a guy who is willing to trade professional services for "professional" services to do your dental work.