If with "dash" you mean the launcher on the left-hand side (the dash is the thing you see when pressing the Ubuntu button in the top-left corner or press the Super key), then this is a duplicate of bug 724986.
If with "dash" you mean the launcher on the left-hand side (the dash is the thing you see when pressing the Ubuntu button in the top-left corner or press the Super key), then this is a duplicate of bug 724986.