As a Canadian dental student currently studying in Australia, I have asked a few dentists (both Canadian and Australian) the same question. From what I hear, the dentists practicing in Australia have said that if you want to live in a big city, you are probably better off practicing in Canada. The dentists practicing in Australia seemed to only find jobs at corporate dentistry chains, which didn't pay that well. On the other hand, I have heard that practicing dentistry rurally in Australia will make you the most money (supposedly more than practicing rurally in Canada). But when I say rurally, I mean rural...in the outback.