To counter this, a lot of dentists use phrases like "pain free" in their ad collateral, and include all kinds of joyful imagery in their offices.
The only problem I've had with my dentist, and it is such a minor quibble that is hardly worth mentioning (except that it is on-topic), is that after every appointment they try to sign me up for wisdom tooth extraction. I'm over 50 and have never had problems with my wisdoms - even the x-rays show them as being perfectly fine. Maybe harder to reach, but they're still clean and healthy anyway. So I just say "No thanks" and schedule my next appointment.
I think my hygienist has an awesome personality, so I don't give her any flack for trying to bring more money into the clinic.