Write a good personal statement. Something meaningful, not some anecdotal nonsense about how you calmed the fears of an anxious patient and was able to provide them with some treatment. Everyone does that.
Tell me what exceptional talent or skill you will bring to the program which will make me want to interview you.
Don't lie or over embellish.
Tell me what you expect to get out of the year. Please do not tell me about treating medically compromised patients or complex cases. We all know that. Tell me something else, like you know what a GPR is.
Grades count, unless you went to Stonybrook, Columbia, Harvard, UCSF, et al.
If your grades are not that high, address this in your essay. Having a part time job at the local recording studio, night club, bar, etc. which kept you out late and unable to study all the time might work.....you get what I mean. Upward trends also work well, and stating how you learned how to budget your time will go a long way in an essay.
EC's: Everyone does give kids a smile, special olympics, mission trips. It's nice, but not a stand out. If you have done something stand out, speak up. If not, how will you stand out in the program?
Long story short...I always see lots of awards from college and few from dental school. I understand you were trying to get into D school and that is why you worked so hard in college. The college awards are not that important.
This cycle the ADAT will not be mandatory. It's coming.
Long story short, there are always more applicants than seats. The squeaky wheel sometimes gets the oil.