Certain radiant quests have brought me to the same area on occasion. A good example would be the Redwood Redoubt, of which I've been contracted to the kill the bandit leader three times now. And though I'm fond of murdering bandits, I'm more fond of stealing their treasure so if there isn't any more for me to take, I don't see the point in questing in that area again.
That said, do the chests and other containers (burial urns, cabinets, bookshelves, etc) in a dungeon ever respawn their contents? If so, any idea how long this process takes?