TG-O Modified Periodontology Chisel, DE The CTG-O Periodontal Chisel is used for removing and recontouring bone with 3.2mm working ends. Both ends are straight. These chisels are used for recovery of bone material by using a push stroke. Product Details TG-O Modified Chisel Working end are 3.2mm in size Used for recovery of bone material Double ended hand instrument Surgical Stainless Steel Completely Sterilized