Sara Kim
 |
 N THE JULY–OCTOBER 2008 issue of Endo-Mail, I wrote about apexogenesis. This time I want to talk a little about apexification. Figure 1 shows the preoperative x-ray of a teenager with a history of pulp exposure due to trauma. The tooth underwent root canal treatment several years ago. You can see that the tooth has been inadequately filled and the gutta-percha is extruding beyond the apex where there is now a periapical radiolucency.
What should you do in a case like this? This can be a challenging case because you have to be extremely careful when trying to retrieve the loose laterally condensed gutta-percha points. You can do more harm by pushing the old contaminated gutta-percha out farther during the process, which can result in the patient’s needing an apicoectomy. I would not use chloroform in this retreatment case. The best way to get those points out is with a broach or Hedstrom. To verify the working length and to make sure that all gutta-percha points are out, take an x-ray. Root ZX will not determine the correct working length with an open apex. After removing the gutta-percha and instrumenting, place calcium hydroxide in the canal for several days until the tooth is asymptomatic.
In the second visit, a good apical seal has to be achieved with MTA. Since 1964, calcium hydroxide has been used for apexification, but MTA came out in 1996 as a better material of choice for this type of treatment. This hydrophilic material has been shown to induce more hard tissue formation and produce less inflammation than calcium hydroxide does. After rinsing and drying the canal, use an amalgam carrier or the MAP System to place the moistened MTA (mixed with water or anesthetic solut ion) into the canal. Use large paper points to push the MTA down to 1–2 mm short of the apex. At least 4 mm of MTA is recommended in the apical third to prevent leakage. Clean the excess MTA on the middle and coronal third of the canal wall with wet paper points and Hedstrom. When the MTA is set, gutta-percha or composite can be used to backfill the canal. In my case, I backfilled with sealer and gutta-percha.
October - December 2009
|
|
| FIGURE 1: Pre-op radiograph. |
|
| FIGURE 2: Verifying working length. |
|
| FIGURE 3: MTA apical fill. |
|
| FIGURE 4: Post-op radiograph. |
|
