My best advice would be to relax! Last year I was in the same predicament as you and remember reading SDN and seeing all these dental students saying to relax, but I couldn't help "trying" to study. I ended up buying the NBDE Part 1 First Aid book and flipping through that a little, but I did make sure to enjoy as much time with friends and family as possible before I moved out of state. You definitely do learn everything you need to know in dental school, so spend your time relaxing because you don't get too too much downtime here lol I did struggle with biochem and some other subjects in undergrad, but I ended up with straight A's my first semester of dental school. It might depend on the school, but I feel like dental school is more organized than my undergrad and the tests are pretty fair. The effort you put in will determine your grades and you just have to learn what the most effective way of studying is for you and go with it. Good luck!