You'll find many threads on the forums that discuss this to no end... I'm the contrarian that thinks it's worth it, but supposedly that amount of debt load is not payable for long periods of time if you look at average dental incomes. If you're flexible enough to work wherever it takes to make money and willing to work hard, then you can pay that off in no time. Are you planning to practice in US or Canada? If you have no other alternatives to make a good amount of money, then you should definitely do dentistry as long as you have a plan.
Generic GP Strategy is:
1. Associate to have startup capital / already have enough money to start or buy office
2. ???
3. Profit
All jokes aside, second step should be to start or buy an office. Popular opinion around here? Buy an office. I did a startup and wouldn't go any other way unless the office was extremely cheap and had potential. Ultimately, to pay your loans back, you need step 3 (Profit) either from associateship or practice ownership. Practice ownership is probably the best way to pay your loans back AND have a decent lifestyle. I would assume that we don't exist/live just to pay off our loans, but have creature comforts as well. What's also debatable is how much profit you can extract/leverage from a dental practice for investing and debt servicing. You'll have a spectrum of dentists starting from those buried in debt and IBR is not even covering interest all the way to paying their loans off in a year or two.
Numbers to think about when making the plunge for student loan debt:
1. How much is your aggregate debt by the time you're working?
2. How much is the interest on your projected debt (monthly)?
3. What's your lowest income potential, medium income potential, and peak income potential?
4. This is where the leap of faith comes... how can you go from lowest to medium to peak? Does going from low to mid to high require capital (it does if you're going to own a practice) or are you going to improve your clinical speed/skills to do more dentistry as an associate/owner?
5. Now, for the risk v. reward weigh in... if your rough calculations show that your interest is going to be higher than your lowest post-tax income, then you need an exit strategy to get out of the cycle of debt (see bullet point 4). Otherwise, you're stuck in a positive feedback loop of your financial situation getting worse and worse. You have IBR as a stop-gap measure to save up money to go through the entrepreneurial route, but you don't have the option to discharge this type of debt. This is where I assume most people falter. If you're going for the clinical speed/skill route as an associate, you need to know how to work under stress with large volume.
6. Invest or pay off loans. If you have investment opportunities that can yield at least 2-3% more than student loan interest rates, go invest. Otherwise, pay it off faster.
It's not easy, but this is my thought process on how you succeed out of the "supposed" death cycle of student loans. I still think it's worth pursuing if you have no other alternatives to making 500k+/yr.