Hi ther, I've switched career from nursing to dentistry 10 yrs ago, and I'm very happy that I did. While in dental school, I met a few people who made a switch from their first careers, e.g I.T, and lots of engineers. As far as I know, they're all happy and more successful now.
When I made the decision to switch, I maintained my part time job as an R.N and started taking pre-req courses at a Community college (cheaper tuition). One semester later, I felt like I need to get the requirements in faster, so I stopped working in general and attended school full time. I was able to get all the courses in that one year, then signed up with Kaplan to take the DAT prep course. I was very glad I did it, because they taught some good tricks to calculate things quickly. I believed Kaplan helped me achieve the score that was a bit higher than average as I was never a good test taker, especially when it was timed.
When it was time for me to apply, I chose to apply to about 12 schools (this was 2001). I applied to the two state schools in my home state, and the rest were private schools. I got my applications in early, so by October, I got 3 interview invites, and by November, I went to all 3. By December 1, I got two acceptances. Luckily, one of it was a state school, so I accepted the offer and made my deposit. I continued to get interview invites later on, but I was no longer interested in them.
I was glad that I went to a state school, because my loan upon graduation was just around $120k. I did not get any help from my folks. I used about 20k from my savings the entire 4 years, and the rest came from loans.
I think if you are determined to get in, you will get in. Dental school is a bit more competitive now than before, but it's not that bad. Try to get good grades in your pre-req courses, and decent DAT scores and you will be fine. I hope my information can help you see clearer about the career change. Best of luck!