I was in a similar position when i was finishing undergrad years ago.
While yes, Histology will help tremendously with the dental school class, I ended up taking evolution and was glad I did.
Heres why.
1) No matter how much you know going into dental school, you are still going to put in a ton of hours regardless.
2) My histology class in DS had specific things they wanted to know and taught no need for extra.
3) It was my last semester of undergrad and already had my acceptance, i was burned out and wanted a small break mentally classes wise before dental school started.
If you have struggled with sience classes in the past I would recommend histology. If you are pretty solid and have a history if excelling in science classes I would take the easier class and enjoy my last semesters in college.