Dr. John V. Lenburg (left) demonstrates how a patientÂs tooth is prepared for fillings with the new air-cutter dental tool, June 9, 1950. The patient is his wife. Dr. O.W. Silberhorn assists him by holding the exhaust tube for carrying away the abrasive powder by vacuum. Called the Airdent, the dental tool utilizes the principle of air-driven abrasives. Tooth structure is removed by operation of a foot pedal switch which controls the flow of abrasives from the tiny nozzle held over the area to be cut by the dentist. Carbon dioxide gas propels the abrasive powder aluminum oxide for cutting cavities and another for cleaning teeth. The rubber mask over the mouth of the patient is used to keep the tooth to be air-drilled dry. 