They really don't care. I graduated 1.5 yrs early.
If anything, its given me more trouble than it was worth. I've had dental interviews that went really well UNTIL they look at my file and see that I graduated in 2.5 yrs. And then they're like wait, how old are you. (shock and wonder!)And when I tell them my age, they tell me that I shouldnt be in such a rush and most ppl are 22+ (I think 24 avg) when they get into D-School.
In their eyes, its like I went from 25 to 15 (real age = somewhere in the middle 😉
I've always been told I come off as much more mature than my age and I think if not for the graduate early/age association, I would never have been told some of the things I was. Boston straight out told me that I have nothing to lose by taking a couple years off since I'm not as old as the other applicants.
I worked my butt off to graduate early (and saved myself a lot of money doing so) but now I have to basically spend all the time I saved in a grad program. I felt like they were basically telling me that they should take the older students first because they have more to loose and somebody else would come get me eventually.
Anyway, one semester early isnt that big a deal. Honestly, I think if people take AP and such in high school, and don't just take 12 hrs a semester, there is little reason anybody needs 4 yrs to get a BS.
I really doubt any dental school will care either way in your situation. If you want it to mean something, you need to do something really amazing and unique with your semester off (and then write about it in your personal statement!). Volunteer at your citys free dental clinic and do docs wo borders or something.