A system for treating a tissue site of a patient includes a dressing filler adapted to be positioned at the tissue site. The dressing filler is comprised of a porous substrate having at least one compressed region and at least one expanded region. The compressed region of the porous substrate is held in a compressed state by a first coating capable of dissolving in the presence of a fluid, and the expanded region of the porous substrate is held in an expanded state by, a second coating.
