Tissy, I saw your post while scanning through the forum and thought I'd give my two cents on the matter. It was really hard for me to study for the MCAT last year and take a 18hour workload during the semester. I found it it tough because those 18hours I took were heavy science related. The DAT is a totally doable test, nothing like the MCAt. The DAT is straightforward. I think you could theoretically study 2-3 hours a night on thet dat stuff like the other poster mentioned, and still do 20+ on the real thing. Instead of taking the semester off, try knocking out some of your easy common curriculum requirements during that semester, make it light.
Also, I don't know if dental school admissions will ask, but they might ask you why there is a gap in your collegiate studies. They might think that you could not handle both classes and studying at the same time, something commonly found in dental school itself. Just my two cents. If you have to have to do it, then alright by all means. You could also try and schedule your dat exam for one of the long holiday periods during the semester. That way you can study at night everyday during the semester, and then have a long break to hit the books hard, and finally take the exam.
Wish you the best,
IndDent