If you're in need of a pediatric dentist in south Austin, I recommend Dr. Gregory Thiel.  He recently relocated to south Austin from north Austin.  He's very friendly and great with children.  He doesn't make you feel rushed at all and answers all questions very thoroughly.  He also doesn't try to push any of the latest fads in dentistry on you as we have found other dentists do.  I live in north Austin, so unfortunately for us he's now a little far.  But, for anyone in need of a dentist for their child I recommend Dr. Thiel.