Grades for acceptance into dental hygiene program?

High School doesn't even matter. What matters at this point is what you've done in college. A 3.5 is pretty solid. In addition it's also good to have done volunteer work as well as being in clubs (being an officer is a plus and shows devotion). It's really about being well balanced and showing devotion. Plus being in activities and clubs makes up for not having a 4.0. Most times having a 4.0 just shows that you don't do anything BUT study and probably suck in communicating with other people (which is bad).