Yes, you will get the bills from the lenders 6 months after you graduate from dental school. You can postpone the loan repayments by applying for forbearance. That’s what I did and I easily got the approval. My GPR salary was only $31k/year. After paying taxes, I only got around $2k/month to live, to spend on the ortho applications, and to pay for the airfares and hotels for my ortho interviews.
When I started the ortho residency, I had to apply for forbearance again. Keep in mind that the loan interests continue to accrue. To avoid this, you have the option to pay just the interest during your AEGD residency.