I think in some places (in WA at least anyway) primary school kids are seen free of charge through the school dental system. Hopefully your little ones will be able to access that soon if it's available over east? But yes it's very expensive to see a dentist normally.

I do agree though that kids sucking on sugary drinks can't help. My little one has never known anything but milk and water and won't do for a few years yet. When I see kids his age (nearly two) drinking juice etc I just can't understand it...