Obtura Max Plunger Shaft Assembly

Obtura Spartan · Wear parts

Roll it on a flat surface. If it wobbles, replace it

Obtura Spartan give you a bench test for this one. The plunger shaft should roll smoothly on a piece of glass or a flat tabletop. If it will not, it is bowed or bent – and they warn that a bent shaft may cause damage to the heater bore. That is the expensive failure this part exists to head off.

This pack: Obtura III Max Plunger Shaft with Plunger Seal · one assembly · seal supplied fitted · for the Obtura III Max

›  Check the teeth: inspected for wear and chipping. Replace the shaft if the teeth are badly chipped, or if slipping occurs during testing

›  Check the tip: exposed metal threads at the tip of the shaft, or other obvious erosion, mean it is time

›  Check it is straight: roll it. A bow or bend is a replacement, not something to work around

›  Seal included: Obtura Spartan supply this as the shaft with plunger seal

How the shaft does its job

Pressing the handpiece trigger drives the shaft forward through a spring-loaded pawl, and the shaft pushes the gutta percha into the heating chamber. The whole feel of the instrument – whether the trigger bites, whether the material moves – comes back to the teeth on this shaft and the pawl that engages them.

When to suspect the shaft rather than the seal

Obtura Spartan list “the plunger shaft repeatedly gets stuck in handpiece” as one of the three triggers for extended maintenance, alongside repeated plunger seal failure. If a new seal keeps going, or the shaft binds after a proper clean, this is the next part to look at.

Asked before buying

Do I need a separate plunger seal too? No – the seal comes fitted. The Plunger Seal Assembly is sold on its own for when the shaft is sound and only the seal has gone.

Will it fit an older Obtura III? Obtura Spartan list this as the Obtura III Max shaft, and note separately that the III Max handpiece will not retrofit to the Obtura III or any previous model. If you are running an older unit, check with us before ordering.

The rest of the system

Shaft + seal · Obtura III Max · REF OBT-823812 · mfr code 823-812