How much of the financial aid award offer should we accept?

So recently, I have received the financial aid offer for the first year of dental school. There are three sections: grant (automatically accepted), and then Direct Unsub Stafford Loan and Direct Unsub Staf 2. Both of those loans have only been offered and it is up to me to accept them. My main question is, how much of the loan should we accept? I don't expect to need to use the max amount of loans the school offers. Also, if we don't use all that we accept, can we turn it back in after the... How much of the financial aid award offer should we accept?
Source: Student Doctor Network - Category: Universities & Medical Training Authors: Source Type: forums