when she was 5. The original dentst said he can't handle small kids and recommended us to HSC. They did an excellent job in 2 times(2 crowns per visit). Not even need to use any medicine to put her into sleep (so she is awake all the time and never cry). The first time the dentst tried to use the smile-gas to calm her down, no result (and no need). So he didn't use anything after a few minutes.