If you need immediate service, you get to a fast track queue and can get free dentist care on the same day. If it's non-acute, you can go to a private clinic which is highly subsidized but does costs some money. But nothing like in the US.
> And is the wait similar for major things like cancer, brain tutor, or heart surgery
If you have serious acute illness, you will not be stuck in a queue. Such a situation would probably be grounds to a lawsuit.