Removing Excess Cement

Young Bui, D.D.S.
Removing Excess Cement

Young Bui

HIS WAS A CASE in which the apex locator did not give me the correct reading and I did not take a working-length x-ray even though the apex locator’s reading seemed a little out of whack. This was a straightforward non-surgical root canal therapy of tooth number 30. (See Figure 1) The apex locator gave me a reading of 18 mm for the distal and no clear reading for the mesial canals. I instrumented the mesial canals to a 24 mm length. Obviously, this was too great a difference between the two roots, and I should have taken a working-length x-ray to confirm it. I thought that the curve in the mesial canals might have made them longer. The other reason for my thinking that 24 mm was the correct reading was the fact that there was no bleeding during the instrumentation, nor on the paper points. The canals were cleaned and shaped using the SafeSiders® technique. They were dried with paper points, and the tips were dried with no evidence of any blood stain.
When I took the mastercone x-ray, I could see the over-fill of the mesial canals about 5 mm out of the apex. (See Figure 2.) I cut back the gutta percha and re-inserted the points into the canals. The problem was that there was a lot of cement along the path beyond the apex from the over-instrumentation, as seen in Figure 3. The other problem was that the apical constriction had been widened from the instrumentation, and that widening would allow more cement to be pushed out when the gutta percha was inserted. What could be done to eliminate that problem? How can you remove the excess cement in the bone area?
The only solution that can remove EZ-Fill® cement with ease is alcohol. I use coarse and extra-coarse paper points dipped in alcohol to remove the cement in the canal and in the jawbone. You have to repeat the cleaning procedure until the paper points come out clean without any stain of cement on them. Once the cement has been removed, you need to plug the apex to prevent the new cement from over-shooting the apex. I mixed up a little putty of MTA and plugged the apex with it. I then filled the canals using gutta percha and EZ-Fill cement. In Figure 4, you can see the MTA plug at the apex and the minimal amount of cement left in the bone area. The patient did not have any post-op pain or swelling the day after. She said that the tooth felt great.

November - December 2008


FIGURE 1	FIGURE 2


FIGURE 3	FIGURE 4

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When hunting for calcified canals or MB2’s, it is a good idea to clamp the rubber dam on the tooth behind and drag it to the tooth in front if possible. This way, the clamp doesn’t obscure your view of the external tooth anatomy, which is necessary to achieve the proper angulation of excavation and avoid a perforation.