Prior to its development in the late 1950s drills had been driven by electricity.
With the air turbine the burr is turned by air pressure and can reach speeds of up to 500,000 revolutions per minute.
This speed generates a lot of heat which can cause irreparable damage to the pulp so the drill is always fitted with a system to direct water at the burr to cool it down.
The air turbine, often known by a trade name of Airotor, was revolutionary as it can cut through enamel and dentine extremely quickly and accurately alongside less vibration and discomfort for the patient.
Today drills can be fitted with a fibre optic light to precisely pinpoint illumination.