This is very true. The key is to either get into a state dental school (debt<200k) or do HPSP scholarship. If you're geographically flexible you can start practices that are on the cheaper side than what you would have to face in a dense city.
Look at how much dental school costs and starting incomes. Also look at the cost to buy a practice. Not all is as it seems. Entering dentistry 20 years ago would have been great because of low educational costs and low practice start-up costs. This is no longer true.