The aim of this study was to clarify the adjunctive effect of enamel matrix derivative (EMD) on expanded polytetrafluoroethylene membrane guided tissue regeneration (GTR)-based root coverage by creating gingival recessions in beagle dogs. Recessions were treated with GTR + EMD, GTR alone, or neither GTR nor EMD (control). The control group was characterized by long junctional epithelium and little bone formation. The GTR + EMD group showed a statistically significant increase (P .01) in new bone and cementum formation compared with the GTR group. The results of the present investigation suggest that the adjunctive use of EMD with GTR promotes formation of new bone and cementum without root resorption in recessiontype defects in dogs.