Yep, you can definitely mention that...
Couch it this way: "I'm sure this dental school will teach me to be a good dentist, and when I graduate I look forward to giving something back to the school if possible, perhaps by becoming an instructor if I'm good enough yadda yadda.."
The key is to present it without sounding arrogant (i.e. don't come across as sounding like you know you are good enough to teach when you haven't even gotten into dental school yet).
Good luck!