The effects of two different polymeric wound dressings and a new collagen matrix (CM) implant on the healing and scarring of full-thickness excision wounds were studied in swine. The synthetic polymers comprised an occlusive O2-impermeable hydrocolloid dressing (HCD) and an occlusive O2-permeable polyurethane film (PUF). The CM implant consisted of an acellular collagen sponge fabricated from purified bovine tendon type I collagen. Wounds were evaluated for granulation tissue--production capacity by measuring 14C proline incorporation into collagenase-sensitive protein. Epidermal resurfacing and wound contraction were measured by computerized morphometric image analysis of wounds made on a tattooed grid. In comparison with air-exposed wounds, the relative collagen synthetic capacity was greater in the granulation tissue of wounds treated with HCD, PUF, or CM with occlusion. Both HCD and PUF accelerated by 40% the epidermal resurfacing over the granulating wound bed. Wound contraction was significantly reduced by CM but was not altered by the occlusive dressings.