Considering that dental school is during the day, and your job is during the day... I'm going to say yes, it's impossible to do both... additionally, you're talking about professional school, NOT undergrad, while we can do UG work while holding down a job, most people don't have time beyond studying to work... So, my answer is no, you can't do both. Save up as much as you can, and remember you'll be making decent money when you're done with school