Improving Efficiency and Safety in Dental Procedures

NSK Ltd. has developed the QuickStopBearing for air turbine handpieces, a type of dental instrument commonly used by dentists around the world. NSK's new QuickStopBearing has an innovative design that can improve the treatment efficiency and safety of air-driven dental instruments.

NSK is targeting 500 million yen in sales of QuickStopBearing by 2030.

Background

Air turbine handpieces are used to drill away cavities and can easily cut through teeth. While in the patient's mouth, the handpiece can spin at the incredibly high speed of 400,000 rpm and the tip of the tool must come to a complete stop before it is removed from the mouth to avoid injuring the patient.

It takes a few seconds for conventional handpieces to come to a stop, during which the handpiece cannot be removed from the mouth, hindering the dentist's treatment efficiency. When the air supply is stopped, a negative pressure inside the head of the handpiece causes “suck back” in which substances in the mouth (saliva, tooth fragments, blood, etc.) are sucked into the tool.

To reduce suck back, some handpiece makers have added a brake structure in the air turbine to shorten the time until rotation stops and suppress the suck back phenomenon. However, the complexity of the brake structure results in a larger head and higher costs.

Features

NSK's QuickStopBearing incorporates a special rubber seal that opens and closes depending on whether air is passing through the bearing, thereby reducing the time until the air turbine stops rotating and preventing suck back.

When the air supply is turned on, the rubber seal opens (floats) and the bearing can rotate as fast as 400,000 rpm, the same speed as conventional air turbine handpiece bearings.

When the air supply is stopped, the bearing's rubber seal makes immediate contact with the inner ring, which stops inertial rotation in a short time and seals the bearing, preventing suck back.

Note that the quick stop and anti-suck-back functionality can be achieved simply by replacing the bearing in an existing handpiece.

Benefits

Improve safety and treatment efficiency by shortening the time to stop rotation.

Prevent suck back, thereby contributing to preventing the spread of infectious diseases (nosocomial infections) and extending the service life of air turbine handpieces.

Improve functionality simply by swapping the bearing in an existing handpiece.

Reduce the cost of manufacturing air turbine handpiece heads compared to air turbine handpiece heads with brake structures.

Reduce the size of air turbine handpiece heads compared to air turbine handpiece heads with brake structures.