Oh, I SO would have left!! And if I had been in the waiting room and overheard this exchange, I would have also left with you. I think you did the right thing. But I think you need to follow it up with a personal letter to the dentist. I would be hard-pressed to believe the dentist shares this same view and certainly needs to be made aware how the assistant is handling new patients. Maybe the dentist does want to see children without the parents, but certainly not on the first visit!!!
And fyi - I agree with you - I can't believe any dentist or doctor anywhere would want to see kids alone.
And also - please go and put this experience under Local Business Reviews so other mamas are aware of how this dentist office does business.
I've taken my son to Dr. Debra Duffy and have had a wonderful experience.
Good luck finding a new one, and thanks for posting for all of us. If you write a letter and get a response, I'd definitely be interested in knowing the response!