Washed Field In Endo

June 26, 1994...Grand Island, NE

(Reprinted from "Automated Endo Update")

"...frequent, copious irrigation."

Every text book on endo that I have ever read says to use "frequent copious irrigation"

and so I asked myself what is more "frequent" than "constant"?

...and in 1972 began irrigating all the while I circumferentially filed

...and I discovered how important washed field is to endo.

Washed field simply means that all the while you are filing, you are adding fresh water to the canal.

The mechanism is simple:

• As you pour the water into the access cavity it gets carried into the canal by capillary action.
• Each inward stroke of the file displaces a volume of water equal to the volume of the file upward and the excess spills out of the tooth.
• On the outward stroke a negative pressure is created at the tip of the file and water rushes in to the previous depth of the file.
• As debris is generated by the file, it is immediately suspended in the water.
• With the next inward stroke that water is pumped up an out of the canal carrying the debris with it.

It is totally unnecessary to force the water into the canal.

It is even unnecessary for the water to HIT the file.

All it has to do is hit the access cavity and capillary action will carry it where it will do the most good.

The role that water plays is very important.

In addition to flushing out debris, it lubricates the files making the cutting faster.

This is true for both circumferential filing and probing.

NEVER PROBE DRY.

Make sure that the canal is wet when probing.

Even if it does generate some hydraulic pressure this is far better than breaking a file because of poor lubrication.

With most of the sonic and ultrasonic units on the market, there is a built in water spray because most of them have either a need to cool the handpiece or have been modified from scalers and thus have a water spray built in.

If a handpiece is used that does not have a water spray, it is necessary for a dental assistant to spray water into the access cavity.

This is really not such a disadvantage as the dental assistant must usually be there anyway to suction the water away so you haven't wasted the DA'S time.

Once you begin using washed field you quickly realize that you have been able to eliminate one of the most time consuming chores in endo, that of irrigating with a syringe and drying with paper points.

Furthermore if you have been using bleach, you must have

• a syringe full of bleach,
• a jar full of bleach to refill the bleach syringe,
• a syringe full of peroxide to neutralize the bleach and
• a syringe of water to wash out the peroxide and then
• paper points to dry up the water.

With washed field and circumferential filing you can eliminate all those syringes and solutions.

Most dentists that I talk to consider it safe enough to use plain old 'aqua tappa' that comes from the city water supply and goes through the handpiece. If you are a little squeamish about this you can go one of several routes.

• First you can shut off the city water and syringe in sterile saline or water using a syringe or a pump bottle.
• Second you can go to a hardware store, buy one of the many garden spray bottles, my favorite is called a 'Bug-Wiser' and replumb it with a dental quick disconnect and fill it with sterile saline and run it through your scaler or the whole dental unit.
• Or you can buy one of the commercial units intended for that purpose. Generally these are a little more expensive and use your compressed air to force the water through your unit. Some of them simply pressurize the air above the water. One actually uses a bag of saline and puts air pressure outside the bag to force the water through.