After Collection of Items they shouldn't re-appear if the player plays the level again

I have a collection of scenes, each one is a level with a set amount of collectibles, you can leave the level if you find all of the collectibles. But if you leave the level and return the collectibles re-appear, this allows the player to effectively complete the entire game by replaying 1 level. Is there any way to stop the stars re-appearing if they play the level again?

The levels that are charged from the scenes, are charged as the scene is, is like a document that cant be saved, this means that if you load it again you will see it without your changes, you can instead save on another file what should and what shouldn't be on the scene other way instead of a file could be saving those values on registry keys