many schools will accept students w/o a bachelors, but i think this is skewed towards better candidates. I was a premed to dental switch too- fyi this can count against you, so to get ready for the interview process do the following: either really exhibit your interest through shadowing dentists and think through why you don't to be a doctor (some good bits are growing HMO dominance, less autonomy) OR just don't bring it up and go with I've always been predent. look at your extracirrics to see which is better for you.
requirements are the same- chem ochem bio physics. upper levels look good, many take biochem. the DAT tests no physics! just bio chem ochem and other sections with perceptual abilities and reading comp and math. I thought it was much easier than the MCAT, but then again I was much more focused when I studied for the DAT.
Competitive, yes! Less so than medical school, but many private dental schools have shut down; also many premeds are switching to dental and bringing their high stats with them.
Honestly I couldn't be happier with my decision to switch. Great lifestyle, less time in school/residency, and comparable earning potential- specializing will help, but many established general practitioners are raking it in too.
As for "residency"- yes if you choose to specialize. After 4 yrs of dental you can specialize if you have good numbers. Varies in length, very competitive, 2 yrs up to 6 for oral surgery.
any q's feel free to pm me