Improvement in Precision Endo Syringe

Cleveland, Ohio_August 31, 1994

Latest Update Saturday, January 17, 1998

Note: This article will remain here for historical purposes.

The Precision Endo Syringe 1977 model is no longer being manufactured.

It has been replaced by the Precision Multi Mode Syringe.

Those who still have on will want to read this but this article has been updated 19Jul95.

Here's where a dimple makes a difference.

The Precision Endo Syringe works as well as it does because there is no leakage between the plunger and the wall of the syringe barrel.

When you load the syringe and then compress the ball in behind it, the plunger pushes the ball and the ball pushes the cement.

It would be neat if it were that simple.

In fact, when you turn the knob on the plunger it pushes on the ball, the rear hemisphere of the nylon ball flattens.

When the ball is compressed enough to move the cement against the back pressure created by the friction of cement against metal and any back pressure in the canal, the ball moves and the cement is extruded through the needle into the canal.

When you turn the knob counter clockwise, the pressure is relieved and the cement stops flowing, BUT the ball is still compressed.

This is a potential source for inaccuracy.

One way to solve that would be to have a harder ball.

This would make it very difficult to get the ball to seal in the barrel.

There is a less elegant but simpler and more reliable method.

If the end of the plunger instead of being flat is depressed, there is less distortion of the ball and thus better control.

If you have a syringe you can do this yourself with a round green stone.

We do it with a little more complex machinery on the syringes sold in the last few years, but the principle is the same.

A little thing perhaps, but not insignificant to accurate sealing and control.

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