about "running it twice"

[Jezco]

Hello!

My question is fairly simple. I did not find the answer by using search quickly so I hope this isn't a post you get every day.
Is it always mathematically correct (more +EV) to run the turn and river twice when you are holding, let's say, top set against over pair with 2 outs, compared to running it only once? please if you can calculate quickly it would help.
also if you include meta-game (barry greenstein theory), does it make your opponents more agressive when they know
you'll "do business" when ever they semibluff into you?
And how does all this affect all together? please I need some help with this. All of this for big bet poker (nl/pl).