> Some dentists prescribe them even when they're not needed, since it won't be harmful to use a tube of the stuff every year, or even every 6 months, and it's profitable to them.
How is it profitable for them? If I get a prescription from my dentist and fill it at a pharmacy, how does my dentist make extra money from that transaction?
Once the sales rep is happy with your performance pushing product, you get invited to expenses paid conferences in the tropics.