i think what helped me was my LOR's and extracurricular. i got a lot of advice from current dentists/doctors that helped me to think 'outside the box.' for example, one doctor suggested i start a dental organization to reach out to under-priviliged kids in the community. so, i started one by conducting surveys, taking photographs, giving seminars, and handing out toothbrush/toothpaste kits. a plus i think would be to do it in an under-served community. something dental-related would help you stand-out from the rest of the pool.
another is LOR. it might be tough, but if there is a particular dental school you have in mind, try to research one of the dental prof's there and try to work for him/her. after a couple months or a year, depending on the personality of the prof, their letter could help you a lot. one of my friends did that for his med school app. i had 4 LOR's, and one of them was from the dean of a university (i got really lucky with this one!).
to the remarks about it being about luck, i agree to some degree. i think that with a little bit of 'luck', and standing out you have a better chance.
i just got accepted this year to the school of my choice, and really this is just my two cents. my gpa before was really, really bad. my post-bac gpa was a decent 3.50. my scores were 20/20/20. also, i applied back in 2008 and i did not even get an interview from all but one school.
it takes time, but with hard work and prayer, i think it can work out.
hope this helps and good luck!