High Overpair vs. Possible Set

[ravensfan]

Sorry, I don't have the converter!

When do you know when your TPTK, or high overpair will be cracked when someone hits their set. Was playing last night on .5/1, dealt AA UTG, called $1 then re-raised a normal $3 raise to $9 as there was one caller on the initial raise. Two players called. Pot was $29. Flop was 7,10, 2 with 2 of the same suit.
Having $70 going into the hand, villains had $110 and $130, neither was too tight. Checked to me, I raised $25 (have $35 left), 1 fold, the BB reraised me all in. I was too committed at this point to fold wasn't I?
He had hit his set and it held.
When do you play your AK/AQ or AA/KK aggressively on the flop when you hit and should have the best hand? When do you pull back when only a set or two pair can beat you (and 2 pair shouldn't beat you if you raise large enough to make it -VE preflop)?

Does anyone have any guidelines on when to fear a set? Or is "that poker"? As in, you gotta play your good cards aggressively?

Thanks