UoP graduates you in 3 years. So in theory as long as UW isn't like $200K cheaper, it's worth it to go to UoP so you can finish earlier, go to your Pediatric Residency, and then start working as a Pediatric Dentist faster and thus starting your repayment quicker.
BTW, every school allows for "opportunity" to specialize. Don't believe others when they say that you have to go to a specific school to get into a residency. People say that because they try to justify going to "fancy" schools that cost a ton of money, but in reality it doesn't matter.
Put it this way, I went to UNLV (not known for being "an elite" school) and I know people who went to Pediatrics, Dental Anesthesiology, Endo, Prosth, Perio, and OMFS. It doesn't matter what school you go to.