As long as I have been playing that has never been the case, nor have I seen it stated anywhere. Drops from dungeons will be either rare, epic, or legendary. The stage determines how many stars that piece has and it might determine the likelihood of getting a legendary in preference to a rare, but I'm not 100% sure on that as farming any dungeon at level 20 very rarely drops legendary quality pieces as it is.

Thanks for the reply. I'm just getting into double digit stages in Dungeons so I didn't know about higher level drops.

Thanks again.