Countries in Europe are generally more lenient then states in the US, when it comes to accepting foreign dental degrees, with some exceptions, of course. The working conditions for dentists vary widely, and I can tell what I know:
The UK has it's GDC (General Dental Council) which you can visit at
http://www.gdc-uk.org. They require some foreign dentists to pass a test before granting them a licence and you can find out on this site if that applies to you. I don't think US graduates will have to take the test. I didn't, my DDS is from Iceland (called cand.odont. there).
The UK has what some call a "double" system. The NHS (National Health Service) is a government insurance system. People who sign up for cover by the NHS must register with a dentist that accepts NHS patients and can get their dental treatment there for a minimal fee. The NHS then pays the dentist the rest of the fee. The dentist also gets an annual payment for each registered patient, for which he must provide some minimal service without charging the patient.
Sounds good? Well it's not. The fees payed by the NHS are rediculously low. If you decide on going to the UK, do not, I repeat
do dot work in a practice that accepts NHS patients. You'll be seeing, and treating, 40 patients pr. day, with 30 min. for a root canal on a molar, 15 min. for a 2 surface amalgam in a molar and so on. I'd advise you to get a job in private practice where the patients are "private" (ie. not NHS). You'll be able to make some decent money and be able to live with yourself.
In Scandinavian countries the market is a little crowded for dentists, unless you're willing to live in the more rural areas. There you can really make money. The taxes in the Nordic countries are generally higher then in the US, sometimes much higher, but they pay for a good health care system with equal access for everyone, (no, or very little, private health insurance), good day-care possibilities, good social services etc.
In the Nordic countries, children, the elderly and sometimes army veterans, get free, or very cheap dentistry. These are usually provided at state-run clinics with salaried dentists. The pay is OK, but the big bucks are in private practice. In private practice there is usually no, or very little, state provided- or private health insurance involved. The dentist determines his own fee, and most make good money. You could also take a look at
this
I have no personal experience with Germany, but I've heard they have a system not unlike the one in the UK, but with more flexibility, so you can work professionally and still make a decent living. There are some very strange competition-hindering laws in the German dental sector, but I really don't know enough to tell you more about them.
I can only encourage you to go abroad to work for a couple of years after you've finished your education. I really is a live-changing move.
Hope this helps.