Maxillary sinus membrane perforation is the most common complication that occurs with the sinus elevation augmentation procedure. Repair of relatively small (5–10 mm) tears is commonly done using fast resorbing collagen membranes and/or by allowing the sinus membrane to overlap on itself. A technique using a cross-linked type I collagen membrane for predictable repair of large perforations (>10 mm) as well as for circumstances in which no membrane is found is described. This technique has several advantages because of its inherent biologic properties. (Implant Dent 1999;8:29–34)