You would have to inform them immediately of this change, since the admissions committee's decision regarding your acceptance is going to be influenced in some part by the coursework that you're saying you're going to complete.
To your specific question: you could only be certain by asking the dental school you'll be hypothetically attending.
In the mean time, talk to the chair of the department of your major. They would probably be willing to help if you came to them with a substitution idea---probably even more willing if you approached them after December 1st with an acceptance in hand so they understand it's all a moot point anyway.
My dept chair pulled off a small substitution for me that saved me a whole semester. But I approached him with a justifiable idea so it wasn't just like "please help me somehow."
