The invention relates to a preliminarily bonded multilayer film (1) for covering a bone defect site (2), in particular in the region of a jaw bone, the film (1) comprising at least one shaping molding layer (3) for molding the film (1) onto the bone defect site (2) and at least one cover layer (4, 4a, 4b) for covering the bone defect site (2), the molding layer (3) and the at least one cover layer (4, 4a, 4b) being substantially completely resorbable.