Tissue regeneration or grafting is promoted utilizing a structure including amulti-layer sheet of collagenmembrane material which includes a purified collagen barrier sheet materialderived from natural collagen-containing tissue, the barriersheet material including a barrier layer with an outer smooth barrier face anda fibrous face opposite the smooth barrier face. Thestructure further includes a matrix layer of collagen sponge material adjacentto the fibrous face. The matrix layer of collagensponge material is resorbed by a body of a subject at a substantially fasterrate than the barrier sheet material.
