Temporary fillings are, basically for a short period of time like, for instance something else needs to be done also, so mean while they would do a temporary filling, get the other stuff done, remove the temporary filling and then do a permanent filling.

In my case the dentist suggested a crown for a broken tooth, but he couldn't do it because of some complication that I had, so I had to see an oral surgent...so mean while he gave me a temporary filling, to seal the broken tooth so I won't have pain etc...