Your DAT and GPA are slightly on the low side for non-minority, however i think even with those stats, you can still get in to a dental school. You have to apply smart!
Do not rush in to a random masters program! post bac in higher level science classes usually are better than masters programs. But consult an admissions rep before you spend the money.
I think your greatest mistake is in your school choices. With your current stats, I think Harvard, NYU, UCLA, UCSF, Maryland, UoP, Midwestern and maybe BU were all out of question. These schools are very stats based.
That means you are essentially applying to ASDOH, USC, UNLV and western.
ASDOH is very focused on ECs, do you have that many volunteer hours? if you do then this pick is justified
USC is a good pick
UNLV is a school for people with high RC scores, they use a formula that heavily weighs RC. You have an 18 which is mediocre.
Western is a good pick
I think you should do a little more research and see if you can add more schools. Remember, application fee is a very small cost compare to tuition you will be paying when you attend dental school.
If you can, you should retake your DAT! if you can pull off 21AA or higher, it will show dental schools that you can do well on tests and potentially can pass dental school