Although nonbiodegradable barrier membranes have been proven partially successful in achieving regeneration of lost periodontium through the principles of guided tissue regeneration, their use requires a second surgical procedure for their removal. The results of a study, in which a biodegradable collagen membrane was used to treat dehiscence defects in dogs, are presented. The membrane was an effective barrier to the downgrowth of gingival epithelium during the early stages of healing and tended to increase the regeneration of new cementum and connective tissue attachment. It was also biocompatable and biodegradable.