New Method for Mixing Root Canal Cement

Dr. Kent Powers, an endodontist in Grand Island, NE keeps reminding me that one of the important steps in using an endodontic syringe to fill root canals is that the cement must be mixed extremely thick. The problem with that is that dental assistants have a lot of difficulty with thick cements.

Fortunately we now have a solution. The solution was actually suggested by Dr. Jim Jordon when I did one of my endo courses at his office in April of 1992. Unfortunately, I never got around to giving it a thorough test until this week.

Jim related to me a way of mixing ZOE that he learned in the military many years before. You cut the finger off a rubber glove or use a finger cot. Put the liquid into the tip of the finger and then scoop the powder in after it. Then pinch the top of the finger closed and simply massage the zinc oxide and eugenol until it is mixed. Then roll the mixed bolus of ZOE out of the finger.

A few points:

• You have to guess pretty close at the proportions.
• If you err, err on the side of not enought powder. It's easier to add powder than eugenol.
• It is difficult to make a thin mix because the ZOE sticks to the latex.
• There is practically no limit on the thickness.
• Make sure that you use powderless gloves or wash and dry the latex before using it to avoid contaminating the mix with talc or whatever else is on the latex.
• You can mix the cement ahead of time and store it in the rubber finger.
• With PCA powder and liquid, about 12 drops of liquid and enough powder to make it thick is a good mix.

Or if you want to see a QuickTime Movie of the extrusion process...

See also the article on New Loading Method For Precision Dual_Mode Syringe