I believe every school and, of course, every situationn is different. Speaking just for myself as an example, UNC fortunately was forgiving of my ugrad academic record (worked, involved in many extra curriculars). I went back to grad school in a research-intensive, thesis based masters (Molecular Bio), earned a 3.7 grad gpa, taught Anatomy labs, 2nd author publication (which raised some eyebrows in interviews), won awards for my research (not dental related), scored 20AA on the dat, showed my face at the dental school many times (so they were able to see my sincere desire to go there-just don't come off as obsessive), and fortunately it worked out. I'm not telling you that stuff to gloat, but I'm just letting you know that it can be done if you really want it. True, a non-thesis masters/post-bac program is fine, but the research/teaching helped round out my apps. Again, every situation is different. It's best to visit/call the Director of Admissions at whichever school(s) you're interested and see what they say, b/c they'll ultimately have the final say. "Don't be shy"-(member of the admissions committee)