|Case of the Month
<< Back to 2003 Case List
April 2003 – Safer Treatment for the Thin Root
Over the past two years,I have begun to incorporate several new technologies into my practice. I initially had some reluctance to move to Rotary Ni-Ti instrumentation because of some initial experiences with unreasonable levels of instrument breakage. However, with the purchase of a proper Torque Controlled Engine and the ProTaper System, I have become very comfortable using these instruments. Hand files are still used at both initial exploration and final gauging of the canals system. In that way, you get the best of both techniques. The result of this change is that my shapes have become more "conservative".
My only concern was that with this change was the feeling that I wasn't heating the apical gutta percha as I had in the past. The larger shapes that I used to produce allowed for good transfer of heat. On the rare occasion that I would pull out an Autofit Cone in mid-pack, I found that the apical sections were cold. They had not deformed that much, especially in long thin canals. Was this new technique producing canals with adequate length but that were merely a "finely machined" single cone technique? Was the heat getting to where I needed it to be. With the thinner shapes, I began to have doubts.
It was at this point that I was introduced to the "System S" or the "Squirt Technique" for filling canal systems. It has been popularized by Dr. John Stropko. I went to John's office in Scottsdale Az. in Oct. of 2002 to see what it was all about. System "S" (Stropko or Squirt) involves using an Obtura II with Schwed Regular Set Gutta Percha pellets ( This formulation is important because it has just the right amount of "flow" that prevents mass extrusion out of the apex.) Once the case is shaped and dried, a size #20 needle is used to express the gutta percha into the canal in one shot. Only very small amounts of sealer are used with this technique and a paper point is used to remove any excess sealer. An appropriately sized Dovgan Plugger is used to immediately apply pressure into the mass and the plugger is held there for 3 seconds to ensure that the GP does not shrink. The results have been remarkable. The anatomy that is produced is extraordinary. Most importantly, I now feel more confident that the gutta percha is indeed "flowing" at the apex rather than remaining cold.
This mandibular first molar was referred to me for endodontic treatment. The patient was a petite young oriental woman with relatively small teeth and very narrow, thin roots. Prior to my use of Rotary Ni-Ti, hand filing a case like this would have meant opening the canals up to a "traditional shape" ( with GG burs) that may have left the case open to furcation stripping at the distal aspect of the mesial root. It also risked blow out during packing of the case using the traditional incremental Warm Vertical compaction technique.
Instead, the canal shapes were prepared more conservatively with the use of scouting hand files as well as the S1 and S2 Protaper shaping files. I finished the case with an F1 and then 25 -.06 GT Profile. Final apical gauging was done with a 25 and 30 hand S files.
Figure 2 - Working length files give some indication of just how thin the mesial root is. Even with a small mesial shift in the radiograph the relative"width'" of the root remains almost the same. This is indicative of a narrow thin root.
Figure 3 - Squirt Technique fill with MB,ML and DL orifices bonded with composite. (Post space made in DB orifice) The results were very satisfactory because much less tooth structure than "normal" had been removed while at the same time obtaining what appears to be a good clinical result.
More conservative shapes are here. The increased flexibility of Ni-Ti files, smaller, better tips that allow for deeper irrigation and less reliance on larger coronal shapes have combined to make the general shape of canals more conservative. However, with that realization comes the knowledge that traditional gutta percha filling techniques may not provide sufficient "bulk" in these canals to allow for heat to be transferred more than just a few mms ahead of any heating instrument. Longer, thinner canals may be in reality obturated by nothing more than a single cone cold technique, albeit in a more well "machined" canal hat more closely corresponds to the correspondingly sized GP cone.
The only alternative remains placing the actual material into the canal system while it is warm. Should you NOT wish to use a carrier based system ( as I do not wish to do), then the System S ( combined with properly shaped canals) provides remarkable apical control in an easy, efficient, effective technique.