The home side had the better of a scrappy encounter but failed to make the breakthrough as their unbeaten run stretched to seven games.
Barry Robson tested Dons goalkeeper Ian McLoughlin from long distance in the sixth minute before the Scottish midfielder crossed for striker Dave Kitson to nod narrowly over the crossbar on the stroke of half-time.
The Dons offered little going forward and Anthony Kay's tame looping header five minutes after the break was as close as they came to a goal.
Blades substitute Jonathan Forte wasted the best chance of the game with 20 minutes remaining. He raced clear on goal from Kevin McDonald's pass only to see his effort take the slightest of touches off McLoughlin and roll wide.
The visitors thought they should have had a penalty in the 76th minute but Dons substitute Patrick Bamford was booked for diving after he went down in the penalty area when through on goal.