I have to say your old dentist is really rather bad, I'm with an NHS dentist that it fantastic.

I've had good and bad on both sides and the person who caused the most problems (That I'm still trying to deal with) was a private practice.

See if you can talkt to the practice manager and exaplain how crap the service was, I can guarentee it but they might be interested.

Good luck with the new dentist!