.....despite what most people on this website say, or get on their DAT's your score has a fair chance of getting you into a decent school. Most of my friends are in dental school and they scored about the same as you, some even less, but most 18 exactly (texas schools at least)... and theyre all in their first year. I would say dont worry about it and apply, however if your REALLY upset about (are a perfectionist) then retake. your gpa is pretty good too. with good LOR, and all that other jazz they like i think ur fine.
BY THE WAY, do you mind showing ur break down of practice testss before going in?