Hey Husker,
First off I'm in Pedo---but best friend is in Prosth. Academics is in desperate need of help----so that is a plus for you. Prosth. is a field where a solid GPA and good boards will do. It's relative but a 3.3+ and high 80s boards should be competetive at most school----especially with your desire to go academic. Obviously some schools are better and demand more. My friend is at Iowa and it is definitely a demanding residency but he loves it. He had over 90 on boards with a 3.6. Make sure you have a great D4 year--assuming you are D3----Take as many difficult cases as you can----take pictures, put together a portfolio of cases and get some good letter of recommendations.
Dr.B