Trephines for the extraction of cylindrical bone grafts Fast, safe harvesting of bone cylinders for augmentation The Trephine Kit offers a wide range of high-quality trephines in fine size increments. These are suitable for the precise and easy creation of cylindrical bone grafts and for bone harvesting. The trephines have a depth of 10 mm and are particularly suitable for use in maxillofacial surgery and implantology. Thanks to the clearly visible depth markings, spaced every 2 mm, the milling depth can be easily and reliably read at any time during use.