I'm currently in my gap year and I think it was the best decision I could have made! I've been able to work full time and save money, while also having the flexibility to do a little traveling. The whole application process itself is also incredibly time consuming--you're applying to schools, possibly filling out supplemental applications, and going to interviews (which sometimes means flying across the country). I was happy to not have to try to schedule applying to schools or interviewing around my exam schedule and school commitments.
I'd say ask yourself if you'd rather get out of dental school a year earlier by applying this summer or if you'd rather take time off to study longer for the DAT (and maybe relax a little before dental school) and apply next year. Make the right decision for yourself! Good luck 🙂