First of all as dock said u need to take a nbde part 1 and a toefl and to take nbde u need to get ECE done only then u can register for ur nbde, once u get a good score u can apply to various schools well there are 29 schools in US which provide IDP program that is a 2-year or a 3-year DDS/DMD program for international dentists. Well all the best for ur nbde.