American degrees are accepted the same as Canada (although a DDS will likely be easier than the other american one), all you have to do is pass the licensing exams and you should be set. Also, public health insurance doesn't cover dentistry at all (unless it were "medically" necessary, that would be a rare occassion) so patients either pay out of pocket or the dentist bill the private insurer. I think the very minimum that a Dentist will earn is about 100K, but likely much more while some established orthodontist might make 500K!