Is it best to finish school, then enroll in the army?

Hello, I'm an upcoming junior at Georgia State Univ. I don't really know much about the army, but each day I try to ask questions or do some more research. I am registered to take my ASVAB next week, but I still have questions. Without getting stipends on contracted monies from the army reserves, I would still be able to go to school with loans. I have a 2.92 and would like to become a dentist. Some people say that not all recruiters will tell you everything about the conditions within the army. I would like to become a dentist for the army, but once contracted, is it possible to get deployed while still in trying to earn my bachelor's degree or while in graduate school? I was also told that just because I would like to become a dentist (even with a high score on the ASVAB), that doesn't necessarily mean I would be able to do it. Some said it depends on the need of the army. While in school,would I have to choose another job to do in the army until I've obtained the degree to become a dentist DDS? Sorry about all of the questions...Is it just best to get my bachelor's and finish graduate school, then to enroll in the army later on? I don't want to get the stipends,etc from the army, then risk the chance of getting deployed, and end up having a hard time to go back to school. What's the point of getting aid for school, if you may not stay in school? Thank you for your time...