I'd keep your job. Every dollar you earn now is worth a lot more once you factor in the interest you'd acquire on a larger loan. From my experience, they adcoms didn't care too much about what you did in your gap year. Spend some weekends shadowing dentists, volunteering, and enjoying your free time.
Thanks for the tips. Basically what I was thinking. I wasn't concentrated on Dental in undergrad because of other interests so I don't know much about what the adcoms really want to see. I'm just doing me lol.