Do adults benefit from flouride?

First let me be clear: I'm not a crazy conspiracy person (...on this) I just don't rely on a municipal well. As far as I know adding fluoride to the private well at my houses is not a thing, good or bad. I did drink municipal water for two years when I lived on campus in college.

That said, is fluoride a benefit to adults or just children?

When I was a kid I got fluoride treatments at the dentist, but then aged out. I've never had a cavity in forty years, but I'd like to keep it that way. Should I still be doing it?

Also no, I'm not using the internet as a substitute for a dentist, just my next dental appointment is in four months. TIA