The result does neither team any favours in the promotion race in League One, with North End now seven points adrift of the top two and the Dons six points shy of a place in the play-offs.
MK Dons had the game's first real chance after 10 minutes when Ben Reeves played in Powell, whose timid finish was comfortably kept out by Declan Rudd's legs.
Preston's best opportunity of a tame, goalless first half came when Joe Garner's header from Neil Kilkenny's corner was pushed away by Dons goalkeeper David Martin.
The visitors came within a whisker of taking the lead early in the second half when Keith Keane's shot came back off a post after Scott Laird's cross had fallen into his path.
Powell then had his second great chance of the night as he beat Rudd to what looked an aimless long ball forward, only for Jack King to brilliantly head his effort off the goal-line.