Hello Prets,
The amount you borrow for school depends on which program you attend. As an international student, I do not believe that you can take Federal Stafford Loans without at least a green card (not sure though). I think you must finance your education using private loans. You will have to contact the program you are interested in applying to and determine which private lenders you can use to take out loans. then, you will know if you need someone to cosign the loan with you. Perhaps a great place to check out would be the international dental forum. There are many people there that probably know a lot more about financing your dental degree from your background than I do.
Good luck!
Jessica