I took 4 "gap years", and don't regret it. I took that much time after undergrad because when I graduated, I wasn't 100% sure dental school was something I wanted, and I figured I shouldn't commit to something until I felt certain.
I worked several years in a different industry, saved up a lot of money, got more clinical and dental exposure, travelled, and became an overall more mature, independent and self-assured person. By the time I went back after my time away, I felt a lot more confident that this was the right path.
Getting back into "school-mode" wasn't hard for me, and I don't feel my age hinders my academic or social ability. I say if you have interesting things that you'd like to use a year to pursue (or you just need a rest), go for it. Dental school will be here, and I think you'll get more out of it if you're able to enter with the right mindset.