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Handpice coupling - why do we have them, how do they work.

Handpiece couplings are used to connect an instrument, usualy a drill unit to the power source supplied by the dental delivery unit via the handpiece hose.  The power supply can be either air or electric, there is also usually coolant air and water supplied. In the case of an air driven handpiece, there is a return path for the exhaust air.

The standard air delivery hose in Australia is usually a six hole configuration consisting of (1) Supply or Drive air, (2) Coolant or Spray Water, (3) Coolant or Spray Air and (4)  Exhaust Air. (5 & 6) are the 2 pins for power to an intraoral light source

Six Hole ISO Handpiece Lead

We can identify all of these function on the KaVo Multiflex® coupling.

KaVo Multiflex Coupling 

The advantage of having a coupling as opposed to screwing the handpiece or instrument directly to the hose (there are handpieces available that connect directly) is the convenience of quickly being able to change instruments during or between procedures.

Identify Which Coupling System You have.

Identify Your Coupling

Here is an example of how manufacturers produce a complete range of instruments to take advantage of a quick disconnect coupling system, in this case it is the Austrian based W&H and their Roto Quick® system.

W&H Roto Quick System 

The disadvantage of coupling systems is that all mediums have to be sealed effectively so as to reach the handpiece or instrument and not escape at the coupling interface. This is accomplished by our old friend the O-ring, so it is of upmost importance that these are in perfect condition.

Any O-ring defect can cause symptoms of low drive speed, low cutting torque, air or water leaking onto the patient from the coupling, or water spilling out of the exhaust air catcher under the delivery head.

If you need to replace any of your coupling O-rings we have a comprehensive parts listing available, CLICK HERE to view them. Please call us for any of your O-ring replacement needs.


KaVo Multiflex LUX® is the registered trademark of KaVo
W&H Roto Quick® is the registered trademark of Firma W&H;
BienAir Unifix L®, Bien Air Unifix® is the registered trademark of BienAir;
NSK MachLit/Phatelus®, NSK Mach®, NSK QD-J® is the registered trademark of NSK.