Hello!
I think you ought to consider and reconsider before giving your all for studies in France. Getting accepted is not that difficult, but passing the massive first-year exam, le concours, is pretty tough. On average some twenty percent manage to pass le concours and are accepted into the second year. You do not need a degree to start studying dentistry in Europe, the course is designed for students who have chosen in-depth studies of chemistry, physics, mathematics etc. at upper secondary school, but the level tends to be somewhat above what one reaches in American high schools, but of course below the level you are at, where US prereqs for DS are met.
So if you chose one of the least prestigious
locations(think Brittany or the north, definitely far away from Ile de France/Paris and the south) your chances are better.
The French usually say that to succeed you should be accustomed to the French educational system(Bac), through French schools abroad or exchanges in France.
As dental... well nearly all education is state-sponsored in most of western Europe(not the east) there are no private universities, the universities have no more spots open than the government allows them to(who in turn usually listen to the national dental associations). This means a pretty selective and exclusive system.
If all you want is to study in Europe I would suggest trying the east; there are several english programmes related to universities in Poland, Latvia, Czech Republic and Hungary. These are easy to get into and(predictably) expensive compared to the low fees in western Europe.
In western Europe there is Germany and Spain which are the "easier" to get into, but the quality in Spain is questionable and Germany... well, if it tickles your fancy go for it! For Scandinavia you need stellar grades, UK less so, but still pretty selective and Ireland not that much. Italy has a tough admissions test.
The course lasts five to six years before you can call yourself a dentist.
All this is assumed you have EU-citizenship, if not, there might be a few more obstacles to deal with, although not too many I would imagine.
Best of luck!!
