I can strongly recommend my dentist, Dr James Woo. I've been having my dental work done with him for nearly 8 years and have always been very satisfied. Same goes for my husband. We also take our 2 children (ages 3 & 4.5) to have a check-up with him.
For the first check-up for a child he'll just look at the teeth, count them, discuss brushing and that's it (unless there's a cavity or other problem). And your child gets a "good boy / good girl" certificate at the end.
The next time around, esp if a small amount of tartar to be removed, he'll do a quick cleaning and the charge will be more.
A nice extra: for the kiddie appointments, the dental nurse dons her Elmo jacket ...
Dr James Woo: 2869 6986, 908 Lane Crawford House, 70 Queen's Rd Central
Dr Jennie Tsai in Causeway Bay is a pediatric dentist and my son loves her and has been seeing her for 7 years now. Her number is 2972-2686/2893-2386. She has 2 sets of real tools, one for her to use and the other is for the child to play around with so he/she knows what's going on.