M.H.
I don't know about Dr. Lantzy, but we use Dr. Bridget McAnthony in Keller. We really like that they let the parents back in the treatment area with their kids...I've found that a lot of other pediatric dentists don't allow this. Her staff is really good about explaining everything to the kids before doing it, and Dr. Mac is very friendly. It is a great atmosphere, they can watch TV while getting teeth cleaned. My daughter was apprehensive before her first visit, but had such a good experience that she's never been scared to go since.
I work with kids in a medical setting, here is some side advice: make sure that you really talk up the dentist and show her that you are confident that your daughter will do a great job and there is nothing to worry about...and show her that you aren't worried either. Then after she's done, praise her, and ask her to tell you about how she is proud of herself. This positive self talk will help cope better for future dental visits.
Good luck where ever you go!