From what I understand different funds offer different benefits, so you might like to Google it and see what suits you best.
I have seen something on TV called Choosi, that help you choose your health insurance. Not sure if it's just in NSW though, so maybe Google that and have a look.

Be aware though, that they usually don't cover pre-existing, so if you've already been to the dentist for something, chances are that they won't cover this treatment. HTH.