I was in your same shoes a few years ago. When I graduated from college I had a sub 3.0 gpa. The end of college, I knew I wanted to be a dentist, but it was impossible because of my low gpa and inexperience with the field. First year after college I worked as a research in a cell biology lab. Second year I found a masters program in biochemistry. I talked to one professors that is a famous clay/nanotechnology researcher about doing dental research (which he had never done but was interested in). I'm now in my second year at that masters program and love it. So far I've created dental filling with far better properties than the current composite fillings. This will have a major impact on getting in to dental school.
All in all, if you get into a masters program that does or is willing to do dental research, you have a higher chance of getting into a program. This shows the schools that you obviously had to learn a lot about dentistry in order to conduct your research. This sets you ahead of a lot of other dental students.
If I don't get in this year, I'll just continue my research into a PhD program which is only 3 extra years. It doesn't really matter how long it takes if you eventually have the job of your dreams.
Research professors in masters programs around your area. Talk to them and find out who is interested in research involving dentistry. If you find someone, talk to a some people at a nearby dental school for collaboration. This will help dental grant research funding of your school, and if the school has no previous dental research, you'll be accredited as starting a dental research program at your school. This is exactly what I did. I was very fortunate to start a dental research program in collaboration with one of the top dental schools in the nation.
If dentistry isn't an interest of schools in your area, apply to a chemistry program. Chemistry is more valuable to dentistry than biology IMO.
