Written by Kenneth A. Koch, DMD; Dennis Brave, DDS; and Ali Nasseh, DDS, MMSc Sunday, 28 February 2010 19:00
In Part 1, we introduced the reader to the benefits of bioceramic technology in endodontics. Additionally, the physical properties of bioceramics were discussed along with a thorough description of the bonding that occurs between the bioceramic sealer (EndoSequence BC Sealer [Brasseler USA]) and the canal wall. A further case was made for establishing synchronicity between the canal preparation and the ultimate fit of a master cone. Part 1 concluded with a detailed description of how to properly use a bioceramic sealer in a one-cone obturation technique.
A “ONE-CONE” TECHNIQUE: WHAT DOES THIS REALLY MEAN?
EndoSequence BC Sealer used in combination with Activ GP cones (or the new bioceramic coated cones) creates an excellent one-cone obturation technique. But, when we talk about a true one-cone technique, what does this really mean? The easiest way to comprehend this is to compare a one-cone technique to obturator based methods. But let’s begin by examining the concept of obturator-based obturation.
Figure 1. Various carrier-based systems.
An endodontic obturator (Thermafil [DENTSPLY], GTX Obturators [DENTSPLY], OneFill [Guidance], RealSeal [SybronEndo]) is a plastic rod, with an attached handle (which in combination is known as a carrier) that has either gutta-percha or Resilon (SybronEndo) attached to it. The first obturator introduced and clearly the most commercially successful was Thermafil. While Thermafil received notable criticism (when introduced) from the endodontic community, it has continued to enjoy some popularity among general practitioners. It is reported that very few endodontists use or would recommend solid core obturation. In fact, in a recently published abstract in the Journal of Endodontics (March 2009), it was stated that, “in a survey of Board-Certified Endodontists and dental school educators, 96.4% indicated that they do not currently use a carrier based obturation system in their practice.” Furthermore, “80% of respondents indicated that they do not teach carrier-based obturation to their students. Reasons for not teaching carrier-based obturation included: difficult to remove, difficult to make post space and not predictable.”1 However, while many of our endodontic colleagues continue to view Thermafil in a harsh light, it does have significance from a historical perspective. We believe endodontic obturators were an attempt to make endodontic obturation easier and therefore, root canal treatment more accessible to the general practitioner (Figure 1).
Figure 2. Conventional retreatment case completed with bioceramic obturation technique: (a) pre-op x-ray, and (b) post-op x-ray. (Case courtesy of Dr. Brad Trattner.)
Figure 3. Conventional case completed with one cone bioceramic technique: (a) pre-op x-ray and (b) post-op x-ray.
EndoSequence BC Sealer and gutta-percha as a synchronized, adhesive endodontic obturation technique utilizes a constant taper preparation and matching gutta-percha cones to facilitate predictable endodontic outcomes. Following cone selection (utilizing the same size master cone as the last instrument to working length), you attach a tip of choice to the bioceramic syringe, insert the tip into the canal no deeper than the coronal third and slowly dispense a small amount of the premixed sealer into the canal while simultaneously backing the syringe out of the canal. Now, using a No. 15 hand file, or something comparable (such as the master cone), proceed to lightly coat the walls with the existing sealer in the canal. Then coat the master gutta-percha cone with a thin layer of sealer and very slowly insert this into the canal, taking it all the way to its final working length. The precise fit of the EndoSequence master cone (gutta-percha or ceramic coated cone) in conjunction with a constant taper preparation creates excellent hydraulics that will move the nonshrinking bioceramic sealer into webs, fins, and lateral canals (Figures 2 and 3).5 Think about what we have accomplished. The silicate components in the bioceramic sealer bond to the ceramic coated (or Activ GP) cones and, at the same time, we have created a bond to the canal wall as a result of the hydroxyapatite that is generated during the setting reaction of the bioceramic sealer. As a result of this bonded obturation, and the ease associated in achieving it, we can now state that the restoration of the endodontically treated tooth truly begins at the apex.
COMPARISON OF CARRIER-BASED OBTURATION VERSUS BIOCERAMIC ONE-CONE TECHNIQUES: PLASTIC CARRIER VERSUS ONE-CONE
When filling a root canal system utilizing an obturator-based technique, you are totally dependent upon the plastic carrier not being denuded of gutta-percha. The solid plastic carrier has the inherent risk of being stripped when inserted into the canal. This usually occurs up high, right at the orifice. This is also very difficult to determine radiographically; whether or not the plastic carrier has been stripped of gutta-percha or Resilon. A one-cone technique, on the other hand, employs a stiff gutta-percha cone or a stiff ceramic-coated gutta-percha cone. In either case, if some of the sealer accidentally gets removed during the obturation process, you still have gutta-percha remaining, not a plastic carrier. Also, when utilizing gutta-percha rather than the “medical grade” plastic associated with obturators, you do not have to overly enlarge the orifice.
Post preparation with any solid core technique, such as a plastic obturator, has some very significant challenges. We really don’t need to discuss the challenges, but more simply ask, “What would you rather make a post preparation in: gutta-percha or plastic?” For even those diehard obturator dentists, we recommend for those canals which will require a post, that a gutta-percha cone technique be used. As mentioned in a recent article discussing obturators and post preparation, “Finally, beware of a manufacturer’s recommendation that their post drill (especially the one with an asymmetric tip) is safe to cut out carriers as they make the post space. We know several talented dentists who have used this method and have inadvertently caused a lateral root perforation with one of these drills.”3
Figure 4. EndoSequence post system.
Additionally, we would like to mention that the EndoSequence technique has a matching post system that solves the problem inherent in the discrepancy found between the final canal shape and available post sizes (and shapes) for most post systems (Figure 4). Here is a solution: The EndoSequence rotary file creates a fully tapered preparation (.04 or .06) from orifice to apex. The corresponding paper points and gutta-percha cones are laser verified to precisely match the final canal shape (last instrument used to length). The EndoSequence post system now goes one step further and is likewise tapered (.04 or .06) to match the exact shape of the instrumented canal. Because of the synchronicity that has been established, there is no need to alter the shape of the root canal preparation to match the post. In a sense, the last rotary file taken to length is acting as a post drill. This concept has also been addressed in a recent article by Dr. Richard Trushkowsky6 when he wrote, “The ideal post should have the same shape as the endodontic preparation, and should be noncorrosive, readily adjusted, and able to be removed without difficulty.” Furthermore, since the dual-cured resin cement that is used to bond the EndoSequence post to the canal wall is also the same material used to create the buildup (EndoSequence Build-up), one can think of this technique as an intra-radicular core buildup with a rebar. Not only is this “post technique” easy to replicate, it is kinder to the tooth and, most importantly, it is safer.7
RETREATMENT OF OBTURATOR-BASED TECHNIQUES VERSUS ONE-CONE
Yes, we know you have heard from your endodontist about the difficulties of retreating obturator cases. It can be challenging! Granted, some companies are now doing a lot of marketing about “how easy” it is to retreat carrier-based obturation. However, once again, we would ask you to be the judge of that. Bioceramic sealer cases are definitely retreatable, yet the issue of retreating these cases has been subject to misinformation. In actuality, retreatment of a bioceramic one-cone technique is quite easy. However, the key to facilitating retreatment is using bioceramics as a sealer, not a filler. (Gutta-percha remains a core component of the obturated root canal.) This is why endodontic synchronicity is so important, and again, why the use of constant tapers makes so much sense (it minimizes the amount of endodontic sealer thereby expediting retreatment). The following is our recommended technique for retreating bioceramic one-cone cases.
COST AND EASE OF USE
Cost certainly should never be the reason why you choose or choose not to use a given system or technique. That said, we want you to always employ a technique that provides great results that you can reproduce time after time (ease of use). This is the key, regardless of the cost factor. But, in case you were wondering, a bioceramic coated gutta-percha cone is about 91 cents, and a solid core obturator is…well, you tell us!8
PEDIATRIC APPLICATIONS AND OPEN APICES CASES
Figure 5. EndoSequence Root Repair Material (RRM) (syringe).
One of the great benefits of new bioceramics premixed in a syringe (EndoSequence Root Repair Material [RRM]) is the ability to treat many young patients in need of pulp caps or other pulpal therapies (eg, pulpotomies). Previously, many specialists considered MTA to be the ideal material for a direct pulp cap because it did not seem to engender a significant inflammatory response in the pulp. Unfortunately, due to price concerns, this methodology was not universally accepted. However, we now have a true bioceramic material (ESRRM) that comes premixed in a syringe (stored at room temperature) and costs far less per application (Figure 5). Hopefully, this will lead to an increased use of bioceramics in our pediatric patients.
Surgical Applications of Bioceramics in Endodontics
Figure 6. EndoSequence RRM (putty).
Figure 7. Retrofill cone made with EndoSequence RRM putty.
As previously mentioned, the bioceramic material to use in surgical cases is the RRM. The RRM is available in 2 different modes. There is a syringeable RRM (very similar to the basic BC Sealer in its mode of delivery) and there is also a RRM-putty that is both stronger and malleable (Figure 6). The RRM in a syringe is obviously delivered by a syringe tip, but the technique associated with the putty is different.
Figure 8. Surgical case demonstrating the use of bioceramic technology: (a) pre-op x-ray, (b) completed case, and (c) 4-month recall (incredible healing for such a short period of time). (Case courtesy of Dr. Ali Nasseh.)
The following surgical case demonstrates the use of bioceramics in a mandibular molar (Figure 8).
FUTURE DIRECTIONS OF BIOCERAMIC TECHNOLOGY
We can fully expect to see, in the future, the expansion of bioceramic technology into multiple aspects of endodontic treatment. Currently, we see its use in surgical endodontics as well as its use as a sealer in one-cone obturation techniques. However, we can anticipate the use of bioceramic technology to have multiple variations in obturation, whether as a sealer, as a material to be extruded from a gun-like device and (we anticipate) even a bioceramic obturator. In fact, a recently filed provisional patent application seeks the use of bioceramic technology with an obturator or carrier based device. Clearly, for bioceramic technology the challenge between its use as an obturator or as a sealer in a one cone obtuation technqiue will only intensify. The only reason (in our opinion) for a company and its advocates to promote a bioceramic obturator technique over a single cone methodology will be in one word: margin. The good news is that the final decision will be made by you, the clinician.
SUMMARY: HOW HAS THE USE OF BIOCERAMIC TECHNOLOGY CLOSED THE ENDO-RESTORATIVE CIRCLE?
Restoration of an endodontically treated tooth should start at the apex. True restorative materials with the ability to bond to dentin are now available to accomplish this objective. The introduction of a user-friendly, room temperature obturation technique that utilizes a constant taper preparation and laser verified gutta-percha, in concert with a new bioceramic sealer (EndoSequence BC Sealer), can be used to achieve this goal.
- Kaban GP, Glickman GN, Solomon ES, et al. Current use and views of carrier-based obturation: report of a survey. J Endod. 2009;35:448.
- Koch K, Brave D. Bioceramic technology—the game changer in endodontics. Endodontic Practice US. 2009;2:17-21.
- Buchanan LS. Common misconceptions about carrier-based obturation. Endodontic Practice US. 2009;12:7-11.
- Koch K, Brave D, Nasseh A. Bioceramic technology: closing the endo-restorative circle, part 1. Dent Today. 2010;29:100-105.
- Koch K, Brave D. A new day has dawned: the increased use of bioceramics in endodontics. Dentaltown. 2009;10: 39-43.
- Trushkowsky R. Fiber post selection and placement criteria: a review. Inside Dentistry. 2008;4:86-94.
- Koch KA, Brave D. EndoSequence: melding endodontics with restorative dentistry, part 3. Dent Today. 2009;28:88-92.
- Koch K, Brave D. A natural evolution: from obturators to one cone bioceramic techniques. Dentaltown. March 2010. In press.
- Nasseh A. The rise of bioceramics. Endodontic Practice US. 2009;2:17-22.
Dr. Koch is the founder and past director of the New Program in postdoctoral endodontics at the Harvard School of Dental Medicine. In addition to having maintained a private practice limited to endodontics, he has written numerous articles on endodontics and he lecturers worldwide. He is a co-founder of Real World Endo and can be reached by visiting realworldendo.com.
Dr. Brave is a Diplomate of the American Board of Endodontics and is a member of the College of Diplomates. In endodontic practice for more than 25 years, he has lectured extensively on endodontics and holds several patents, including the VisiFrame. Formerly an associate clinical professor at the University of Pennsylvania, Dr. Brave currently holds a staff position at The Johns Hopkins Hospital. He is a co-founder of Real World Endo and can be reached by visiting the Web site located at realworldendo.com.
Disclosure: Drs. Koch and Brave are co-developers of the EndoSequence rotary file and EndoSequence BC Sealer/Root Repair Materials, Brasseler USA.
Disclosure: Dr. Nasseh reports no conflicts of interest.
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