In an experimental study using the Göttingen minipig, Gore-Tex, Gore Resolut, and Vicryl barrier membranes were tested for their efficacy in guided bone regeneration. The results were compared to those of autologous periosteum. The strongest reossification was seen in the bone defects covered with Gore-Tex; however, time-dependent disintegration phenomena, which had already been observed in preliminary examinations, were clearly established. After investigations of cell cultures to which human macrophages were added, the latter findings can be interpreted as the result of a physicochemical process, since a direct attack by the macrophages was not seen in vitro. Of the membranes used, the absorbable ones tended to collapse, depending on the size of the defect that was used, and they did not enhance reossification as much as did the permanent membranes. The periosteum-covered defects showed a satisfactory degree of regeneration, and no differences were observed between freely transplanted and pedunculated periosteum. Keywords: absorbable/nonabsorbable barrier membranes, disintegration phenomena, Gore-Tex membranes, guided bone regeneration