It depends on the particular schools and the situation I think. Different adcoms might weigh DAT and GPA differently, and the size of the applicant pool in a particular year might be a factor too (larger pools means more qualified applicants and the adcoms can afford to be choosey).
I got a 21 academic and 24 PAT on the only time I took the DAT, which is pretty respectable. My undergrad overall and science GPAs are both 3.1 only. None of the dental schools I applied to accepted me on my first attempt because of my GPA.
So the short version of the answer is, IT DEPENDS!
Like UBTom says, it depends on a lot of factors. But applying early is the key, though.
I would say if you have around a 2.8-3.1 aim for 21+
it really matters if you are passionate about dentistry as well. numbers are only needed for the interview, once you are at the interview then numbers really don't make that much of a difference (lets hope so).
For full-time students, finishing an MS in Biology is doable in 1 year... But I had to keep a roof over my head and put bread on the table, so I worked full-time and did the MS in an evening program, and that took 2 years.
The 4.0 GPA I maintained while in the MS program is what finally got me over the hump and into dental school.
UMDNJ - early denial (not New Jersey resident)
Columbia - interviewed
NYU - interviewed
SUNY Stony Brook - interviewed
UB - interviewed
UConn - early denial (not Connecticut resident)
Temple - interviewed
Tufts - interviewed
BU - not interviewed
No acceptances from any of the schools I applied to.
My second attempt in 2000:
Columbia - waitlisted
NYU - accepted
Stony Brook - denied
UB - accepted (where I am now).
For my second attempt, I applied only to the schools in New York State because as an NYS resident it is easier for me to get into those schools, more affordable (the two public schools at any rate), and closer to home.
If you've had a strong upwards trend in your grades and strong DAT scores (20+), the schools seem to be more willing to look past an unfavorable GPA. They generally want to see additional upper division coursework in the sciences to prove that you really can succeed in a tough dental curriculum. If they can see that you are a serious student, it will help your situation greatly.
I had bad grades during my first 3 semesters of college which left me with a 3.09 overall and 2.6 science gpa. I had a stronger performance during my last 2.5 years of undergrad, and am currently taking some post-bacc courses (with a 4.0 GPA). I did pretty well on the DAT (disregarding the PAT), and have been offered 3 interviews so far. I am proof that if you: 1) apply early, 2) do well on the DAT, and 3) do well in your upper division work, that dental schools will at least give you a look. (Now, let's just hope that this translates into an acceptance.)
For the 1998 cycle I applied early. Back then only the paper version of the AADSAS application was available, and I sent mine out at the earliest date they would take them in October 1997. Nowadays with the on-line applications you can send them out as early as June, right?
Anyway, I also sent out the secondaries no later than 5 business days after I received them in the mail.
The reason why I went for the MS? Both Dr. Milton Bell (then director of admissions at NYUCD) and Dr. Robert Joynt (chairman of the adcom at UBSDM) suggested I go to an MS program to bolster my record.
It took a while but I finally got my foot in the door.
My GPA is pretty much it-- That's the weakest part of my application. Everything else was up to speed: DATs, experience in the dental field, research, etc. That's pretty much what all the adcom directors told me, and two of them suggested that I go for an MS first to show that I can hack the material.
Also, in my first attempt I applied to a lot of out-of-state schools. Granted some schools like Tufts are not as heavily-biased against out-of-state applicants, what I should have done is concentrate on the schools in my state where I had the best chance of getting in (the four New York schools).
Plus I might have applied in a year during which there were a lot of applicants, which meant the dental schools could afford to be choosey.
My second time around went a lot smoother I'll tell you that..