Implant failures often give rise to significant bone resorption, which can jeopardize future implantation and cause esthetic and functional problems. One technique now commonly accepted is guided tissue augmentation (GTA) prior to reimplantation. A resorbable collagen membrane clinically tested for 3 years has provided predictable results both in GTA and in guided tissue regeneration (GTR). This article reports a study at 3 and 6 months after use of this collagen membrane in ridge repair. New bone formation, first woven in texture, then lamellar, was observed. Resorbable collagen membranes can provide for ridge enlargement and bone repair without inflammation during healing. Schlagwörter: bone healing, collagenic membrane, guided tissue augmentation, histologic study, osteoformation