M.S.
Without a doubt it's Dr. Helen Ragsdale. Someone else recommended her already, but I second that!!
http://www.austinlaserdentist.com/
I've been going to her for about 19 years and won't let anyone else touch my teeth. I don't really like the dentist, but she's so gentle. You don't even feel the shots! She's awesome and you won't be sorry you went to her. I've recommended her many, many times and she has about 25 loyal patients from me and other friends of mine who all love her.
Good luck!!