Instrument Rubber Dam forceps Ivory used to carry the clamp to the tooth. They are designed to spread the two working ends of the forceps apart when the handles are squeezed together. The working ends have small projections that fit into two corresponding holes on the rubber dam clamps. The area between the working end and the handles has a sliding lock device which locks the handles in positions while the clinician moves the clamp around the tooth. Forceps do not have deep grooves at their tips or they become very difficult to remove once the clamp is in place. This instrument is necessary to open the clamp and position it around the tooth. The Ivory forceps are preferable, because they allow the dentist to apply direct pressure toward the gum, which is frequently necessary to position the clamp securely below the bulge of the tooth crown.