Air Motor – A slow speed handpiece without internal reduction gears or attachments,
usually rotating at speeds near 20,000 rpm.
Attachment – a nose cone or angle that quick disconnects on and off the front
of a low speed motor to provide various bur holding options.
Auto Chuck – A mechanism enabling the operator to change a bur without the use
of a wrench, by pressing a button or raising a lever.
Autoclave – A steam sterilizer which destroys all living organisms through
the medium of heat and pressure. Temperatures are raised to 270-275°F
while the pressure is raised to 30 psi.
Bur – A rotary dental instrument, which when placed in a handpiece is used to cut
or carve tooth structure. Burs come in a variety of shapes and sizes and can be
made of high speed steel, carbide, or diamond coated material.
Canister Turbine – A closed cylinder which houses a rotating turbine assembly
inside the head of the handpiece. Designed for easy replacement.
Chemiclave – A sterilizer which uses a chemical to generate chamber pressure
instead of steam. The absence of water in the process reduces rust and oxidation
Chip Air – Air supplied through the handpiece from the dental unit tubing to the
cutting surface to cool the tooth or disperse the water spray, while flushing away
residual material resulting from the removal of tooth structure.
Chuck – The part in the handpiece turbine used to hold the bur.
Collet – Another word for the chuck mechanism.
Connector – Attaches the handpiece to the dental delivery unit that supplies air
and water to the handpiece. There are four types of standard U.S. connectors.
They include the 2, or 3-Line (also called a Borden) and 4-Line. The 4-Line (also
known as a Midwest) is the most popular connector. In a 4-Line connector, the holes
are (1) drive air, (2) chip air, (3) water, and (4) exhaust. Sometimes a fifth line
or hole is added for a fiber optic bundle. A newer type of connector, 6 Pin, is now
available which provides an electrical connection for a fiber optic light bulb. Hole size
and location are indicated by a standardized ISO specification.
Contra Angle – The front section of a handpiece which changes the desired angle
to provide better bur access and visibility to the operator during use.
Coolant – Refers to the water spray directed at the bur to cool the tooth when cutting.
Doriot or Universal Angle – Any angle that operates on the front of a nose cone
that has a protruding shaft designed to fit into the nose cone chuck.
Drive Air – The compressed air used to rotate the turbine in a dental handpiece.
“E” Type Motor – A motor with a standardized male fitting (connection) that accepts
attachments with the matching female connection.
End Cap – The cap, or cover which is removed to install the turbine.
Exhaust – The air discharged from a dental handpiece after spinning the turbine.
Fiber Optic Handpiece – A handpiece through which a transparent fiber or cellular
optic bundle transmits light to illuminate the oral cavity.
Friction Grip Chuck – A chuck which holds the bur strictly by friction generated
from an internal spring assembly. The bur is simply pushed in and out of the chuck
with a special tool using force to overcome friction
Handpiece – A handheld device which engages rotary instruments for cutting, cleaning
or polishing the teeth. A handpiece can be belt-driven, pneumatic (air or gas driven)
High Speed Handpiece – A handpiece which operates at a speed greater
than 100,000 RPM.
Jacobs Chuck – A mechanism which utilizes a wrench to tighten the chuck.
This design incorporates slots which create jaws that are compressed onto
the bur shank when tightened with the corresponding wrench.
Latch Angle – An attachment that holds a specialized bur which is mechanically
retained by the use of a swinging hook that engages a recess in the bur shank.
Low Speed Handpiece (or Slow Speed) – A handpiece which operates at speeds
ranging from 5,000 to 20,000 rpm.
Lubricant or Oil – A liquid applied to moving parts of a handpiece or attachment in
order to reduce friction, heat, or wear, or applied to surfaces in close contact to
prevent them adhering to one another. May also include a solvent for cleaning.
Nosecone – A straight attachment used with a slow speed motor which holds a lab
type bur (3/32” shank) or any standard doriot attachment.
Prophy Angle – An angle that holds a brush or cup containing prophy paste used
by a hygienist for cleaning teeth.
Quick-Disconnect – A handpiece attachment or fitting designed to allow easy
separation of the handpiece from the supply tubing.
Replacement Cartridge – Another name for a high speed turbine, usually self
contained to allow easy replacement.
Rotary Vane Motor – A type of low speed motor utilizing small vanes instead
of a turbine to trap drive air in a rotor assembly to generate rotation.
R.P.M. – Revolutions Per Minute. A unit of measurement indicating speed.
Straight Handpiece – Same as a low or slow speed handpiece. Often refers
to a handpiece with a nosecone permanently “fixed” to the motor.
Swivel – Instead of threads at the rear of a handpiece, the swivel is usually
a separate part that threads into the supply tubing and incorporates a quick
disconnect. Designed to allow the handpiece to rotate where it attaches to the
air supply tubing in order to reduce fatigue on the operators wrist.
Turbine – Located in the head of a high speed handpiece, the turbine holds the bur
or cutting instrument while rotating from high pressure compressed air. A turbine
consists of five components: spindle; chuck; impeller; bearings; and two “O” rings.