I stayed with them until they dropped me for forgetting one too many appointments (I tend to find it difficult to remember things six months apart). I didn't like going to the dentist but I thought it was always going to be like that.
At this point, I went to the practice my boyfriend uses, and my dentist is now Miss James. She is very kind and reassuring, she lets me stick my hand up if I feel nervous so that she can back off for a moment, she's never hurt me (even in longish filling procedures -- I haven't got a root-canal incident to compare), and I've never felt guilty because I'm a bad patient--which I felt all the time at the other place. She's wonderful. She seems to think of details the other dentist never did: giving me a moment's rest in case of nerves, putting dark glasses on me so I don't get the sense of FREAKOUT INTIMIDATION DENTIST LIGHT :-),
I have my checkup appointment in September on the kitchen calendar, iCal and my Blackberry so as not to miss it, on the principle that dentists who make me feel less-worse about going to the dentist are worth their weight in whatever.
It's not necessarily bad service, but it's useful information: if you're a nervous patient it's worth finding a practice that you feel comfortable with, even if the one you try first advertises that it's good at putting patients at ease.