MWU-AZ total cost is 428K (https://www.midwestern.edu/Documents/Financial Aid documents/COA Forms/2015-16 AZ/Dental _ AZ 1516 final.pdf). This assumes no further tuition increases, which WILL happen.
40K a year is only going to result in 400K after 10 years.
Total cost of attending MWU-AZ is 428K + interest.
Over 10 years, you will pay a total of 557K for a MWU-AZ Dental education...That's 129K in interest.
This assumes 7% interest rate and $4644/mo payment.
As an aside, you CAN live frugally for less than 50K a year, depending on the location. However, I think your 50K includes a yearly savings/rainy day budget, in which case 50K is reasonable.
I was speaking more generally and thinking of about 400K total. I was thinking the 50K after loans, insurance, 401K's, etc. Heck, 30K would be reasonable in many areas of the country, at least before kids come along.