My advice would be to go to the cheapest possible school. Big names like Harvard and Penn will not do much for you in the long run. There will be those who argue that but the reality is that if you are interested in specializing and do well anywhere you go, then you will get into a program after graduation. I can say this because I interviewed and sat in on the ranking of applicants at my residency. In fact, most people I have met actually did much less clinical dentistry and more didactic work at the ivies. In the end, everyone evens out in private practice but there isn't much value in paying 100k more for tuition at one school vs another.
In my case, I took a year off to get in-state status so that I could pay cheaper tuition. With living costs I graduated with 140k in debt. My interest rate is not really applicable to others because it's 2.8% right now and in 4 years of straight loan payments it will be 0.7%. I was able to consolidate at a really good time.
Go to the cheaper school and you will be much better in the long run. Don't kid yourself...300k is an incredible hole to be starting from. Regarding production since others brought it up...it depends on the situation. Two months out in private practice for pedo I'm producing about 5-6k a day and am working 4 days a week. That's without hygiene or films included so if I were owner it would be more around 8-9k/day production.