I'm fortunate, I've had the same dentist for 23 years and he's been consistently honest with me about what's necessary and what's not. I don't know what I'll do when he retires.
Same for me. Same dentist for 30 years who was also a family friend. He retired last year. The plus side is it's a smaller community, so I already have a new dentist if I move back that I personally know and trust, but I don't know what I would've done if I wasn't that lucky.