I think it's getting harder and harder to find a good niche to open a brand new practice and be successful for any dentist let alone one fresh from D school. Each area has it's own economy/population. It's not just a matter of taking out a loan and going for it, there is also the issue of dentistry and management of dental practice, I make the argument that it's probably more prudent to work as an associate for 2-3 years and tough it out during this time (you still be making ~150k), this, in my opinion, will allow you get a good feel for what you feel comfortable with in terms of procedures, also you can learn from other dentists in practice, not only about the dentistry part but how to manage the practice, this includes the money part (fees, insurance, labs, bills...etc) all the way to staff members and the associated headaches. By that time, you will also get a feel for the area and where you want to set up shop, I worked in two different areas for dentists with different mindset, one had one practice with 2 other associates and was more high end, the other was an HMO mill with 4 practices across town with around 10 associates and 12 hyg working like bees!. Both were making a great living, albeit with different approach.
I think it's probably less risky to buy in than to open from scratch, granted you have to know what your getting into in terms of numbers, but you can always change things as you go.
Ok I think I'll stop now!
Oh and if you guys think that we are paying too much taxes, just ask someone who lives in Europe how much taxes they are paying!