I think Allegri would be happy with a 0-0.
But it's very unlikely if Dortmund plays there game - and they probably will.
If they succeed in sufocating Juve, they'll score on Juve's mistakes.
If they don't, their fragile back and up high defenders may be found wide open like other teams have found.
A 0-0 would be very possible if Dortmund would approach a more cautious posture.
Gotta take very good care of the ball, play on the counter, use a lot of movement upfront and finish well.. that's basically it. Start it defending well. We haven't been doing that lately, and have been taking care of the ball very poorly, specially with Pirlo. If this improves, chances are good.