By enrolling in a 2-3 year long DDS/DMD Advanced Standing program, you are enrolling straight into the D3 and D4 years. Once you attain your degree, you are free to practice however you choose.
do you directly get into a dds/dmd program after completing bds from another country, or do you have to apply for a licence exam first and then apply to a dds/dmd program?
You would first have to complete pre-requisites such as the INBDE, TOEFL, and ECE. Afterwards, you would go through the Advanced Standing DDS/DMD application process. The licensure exam (ADEX) may be completed later on during your time as a student should you choose to sit for it.