Loading the Precision Endo Syringe

Indianapolis, Indiana (1994 AGD meeting)

Latest Update Saturday, January 17, 1998

I met one of our previous attendees at the AGD meeting the other day and he reminded me that although some things seem simple to those who use a device or technique every day, habits develop that prevent us from using it properly.

A good example of that is loading the Precision Endo Syringe.

So for reference here is the technique with a few tips that may be valuable for some of you.

  1. Mix the cement very thick.
    • Some say as thick as cream cheese.
    • Actually it is more like frozen cream cheese.
    • The thicker it is, the less toxic.
    • The thicker it is, the more radio-opaque.
    • The thicker it is, the easier it is to control the flow of cement.
    • (See the article on the hollow ended plunger.)
  2. Mix the cement on a glass or ceramic slab.


    When you mix on paper of plastic, you always end up with paper fibers or plastic scraped up into the mix.

    This can very easily plug up a 30 gauge needle.

    • Note: We are now mixing the cement in a finger cot or preferably a finger cut from a latex glove.
    • 12 drops of liquid and
    • enough powder to make it THICK
    • massage until thoroughly mixed
    • invert latex glove finger and get ready to load
  3. Pass a dry pipe stem cleaner or one of the ball valves through the syringe before loading it.

    A piece of dust, rust, set cement or any kind of debris can plug a syringe.

  4. Do not load a syringe while it is still hot from the sterilizer.

    Heat causes ZOE to set rapidly.

  5. Make sure that the inside of the syringe is dry.

    Water is a catalyst for ZOE.

  6. Make sure that the slab is dry.

    Ditto above.

  7. Do not attempt to mix too little cement.

    You need enough that you can avoid trapping air in the cement when loading.

    And do not ask your assistant to mix with a cement spatula.

    It's too small.

    Get a Buffalo #2 plaster spatula.

  8. Pile the cement up in one place on the slab.
  9. Remove the barrel from the plunger guide knob..
  10. Identify the front from the back.

    The front has small threads, the back threads are large The syringe is loaded from the BACK end.

    The end of the barrel is repeatedly plunged downward into the mass of the cement on the slab.

    Do not attempt to nibble away at the edges of the cement mass.

    This usually ends up trapping too much air.

  11. It is not necessary to load the syringe barrel full.

    Generally after you have loaded about half of it full, you can see the cement from the front end.

    In fact loading a syringe completely full is not a good idea.

    The more cement you have, the more air you have.

    What prevents good control of cement flow is air in the syringe.

    Half a barrel is usually more than enough for several canals.

  12. Drop the white nylon ball into the cement.

    This keeps it from rolling all over the place.

  13. Pick up the ball with the back of the syringe.

    Push down on the ball with the barrel onto the slab, force fitting the ball.

  14. Wipe the back end of the syringe with a tissue.

    It is far easier to clean fresh cement off the outside threads of the barrel than to dig SET cement out of the plunger guide knob.

  15. Push on the ball with the plunger until the cement comes out of the front end of the barrel.

    Wipe excess off the front with your finger tip.

  16. Load the hub of the needle with cement.

    If you fail to do this there will be air trapped between the outside threads of the syringe and the inside threads of the needle.

    This acts as a shock absorber and prevents smooth flow and control of the syringe.

  17. Make sure a good washer is in place on the syringe before attaching the needle.

    These washers last a long time but when they go they will get a small crack that often can be felt by running a finger nail around the washer.

  18. Screw the needle down until it contacts the washer.


  19. Now put the plunger guide knob back on the syringe.
  20. Take a pair of pliers or a 1/4" wrench and tighten the needle onto the washer slightly compressing the washer.

    Too much pressure will crush it and cause it to leak.

  21. Check your work by turning the plunger until cement flows.

    Turning it backwards should stop the flow.

    By turning it forward and back you can get it to a point where the slightest clockwise turn will restart the flow and slightly counter-clockwise will stop it.

    If cement continues to flow, you probably have air trapped in the mix.

    The only solution is to start over with a new needle.

  22. If the liquid has oxidized to the point where it is brown, it is difficult to mix enough powder into the eugenol and the cement will be more toxic.
  23. If you have not yet looked into the new Multi Mode Precision Endo Syringe for sealing and filling the apex, do so immediately.

It is really a new standard of care in endo.

E-mail your comments to drjack@BetterEndo.com

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