Validating Endodontic Concepts

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Validating Endodontic Concepts

Postby BarryMusikant on Wed May 10, 2017 11:26 am

Validating Endodontic Concepts

When we perform an endodontic procedure or even prior to that when we purchase an endodontic instrument to accomplish a task, we are using technology that we are convinced will give us the best results. Most often, the process of convincing us came via broad repetitive advertising, a personal visit by a company representative or trying the approach in a continuing education program sponsored by the manufacturer. In short, in one way or another, we are most influenced by an extension of a company’s marketing arm.

If instrumentation is the task under discussion, a relevant aspect would be just how well it cleans canals with a variety of different anatomies. As dentists, we really don’t know how well we are cleansing the canal walls. We can judge whether or not we have fairly dense obturation material the length of the canal, but that doesn’t really tell us whether or not we have thoroughly debrided the canal in three dimensions. Indeed, we often assume a canal is well instrumented when we see a dense fill in our mesio-distal periapical x-rays even though this image tells us nothing about the bucco-lingual anatomy of the canal along its entire length. This information is crucial to a critical evaluation of instrumentation systems and can only be accurately assessed with in depth examination of the shaping process after it is completed, something that can only be done on extracted teeth.

The only accurate assessment is one made in three dimensions. Micro ct technology is one option that gives us the ability to visualize the anatomy of extracted teeth in three dimensions with extreme accuracy. Furthermore, we can access the effectiveness of instrumentation applied to a range of pulpal anatomies from simple to complex. It gives us the ability to measure the claims made for new instruments against the reality of their results. These results produced by a group of Brazilian researchers (Versiani, Pecora and Neto) clearly challenge the claims made by some major manufacturers regarding their products. One company touting the use of a single file system used in interrupted rotation leaves large amounts of untouched pulp tissue in the buccal and lingual dimensions that extend beyond the conical preparations these files make. The manufacturer claims that thorough and rapid debridement results routinely with the use of this file. The micro-ct says otherwise.

Another company claims superior debridement with minimal loss of dentin by using a 1º tapered NiTi file that incorporates multiple undulations along its length stating that these deviations from a straight instrument gives these instruments the ability to remove debris from all the irregularities that might be present in various pulpal configurations. The claim is less removal of dentin and superior removal of pulp tissue. Again a micro-ct scan of a lower molar shows large amounts of untouched pulp tissue remaining after these instruments were employed.

This type of data is readily available. A simple search in google images finds this type of information in abundance under Versiani, Pecora and Neto.

In light of these findings, we must conclude that for many of us, our decisions are based on the easiest way to attain information and that is always going to be from sources that are purposely targeting us for the unexpressed purpose of increasing sales. Our dilemma is obvious. We can take the easy road and base our purchasing decisions on those companies that have the most convincing marketing arm or we can seek out non-commercial sources that give us doses of reality.

Since scientific conclusions can be in conflict with commercial messages and knowing that the vast majority of dentists will follow the path of least resistance, those determining their choices on scientific grounds will often be in the minority and look like the odd one out, going against what is assumed to be conventional wisdom. It reminds me of a time years ago when I was teaching a course discussing the advantages of reamers over files. Since most dentists were taught files, the less efficient of the two, I asked the attendees if anyone was using reamers. One older fellow raised his hand and said he had used reamers, but switched to files. Surprised I asked him if he found the files better. No, no was the response, the reamers worked far better. Then why did you switch back. He said I figured I must be doing something wrong because everyone else was using files. There’s a lot of truth in this encounter.

We all tend to follow the pack rather than setting off on our own quest for discovery. This is true for many things, but in terms of endodontics, I can give specific examples of research that deviates from commercial claims. One need look no further than the critical review of Resilon many years after its introduction as a superior obturation material.  In terms of instrumentation, look at the claims made for Wave One and the micro-ct scans of their effectiveness in molars. The same is true for the claims made for the XP-3D shaper and finisher.  A significant gulf exists between documented research and commercial claims.

Another way to make an accurate assessment for the claims manufacturers make regarding their instrumentation products is to use them in transparent replicas of teeth with complex pulpal anatomy. 3-D printing gives us the ability to cleanse teeth made of tough see-through plastic with anatomy as complex as those used in micro-ct studies. Rather than visualing the effectiveness of instrumentation on the amount of remaining pulp tissue via micro-ct scans, we can assess it directly by microscopic examination after instrumentation. We chose this route when we instrumented the canal space in the distal root of a mandibular molar model. It consisted of a disto-buccal and disto-longual canal with a thin isthmus linking the two not unlike the specimens that were examined by the above micro-ct scans. Rather than use a rotary system neither interrupted or continuous, we shaped the canal space and the common isthmus dividing them using relieved twisted stainless steel reamers in a 30º handpiece oscillating at 3000-4000 cycles per minute.

The initial instrument was an 06 tipped 02 tapered stainless steel reamer that was thin enough to make an initial entry into the isthmus between the two canals as well as negotiate rapidly to the apices of these canals. By confining the motion to 30º the instruments are virtually invulnerable to breakage allowing them to be used vigorously in the bucco-lingual plane giving them the ability to reach the tissue ensconced within the thin walls of the isthmus. Approaching instrumentation in this manner provided the means to shape the canal with minimal loss of dentin in the mesio-distal plane while removing the bulk of tissue in the disto-buccal plane.

As the obturation x-ray illustrates, the entire canal space including the sheath of tissue described as an isthmus is cleansed and obturated, something that was not accomplished with the other two systems. It is axiomatic that a system is superior if it can remove more pulp tissue while sacrificing less dentin. This task can be accomplished with great efficiency, low cost and the virtual elimination of instrument separation, the key to pulp removal and dentin preservation.

Once the dentist knows that a system is pretty much impervious to breakage, it can become highly adaptable to all pulpal anatomy. If the canals are quite thin we always have the option to start with the thinnest 02 tapered  06 tipped stainless steel reamer.  An instrument of this dimension is flexible enough to negotiate the most curved of canals. Used in the 30º oscillating handpiece at 3000-4000 cycles per minute, it routinely shapes canals for larger sized instruments that in turn shape the canals further without distortion or the creation of ledges. With a typical apical preparation of 35-40 and limited to 02 tapers we have the means to internally route any canal and selectively target those areas where pulp tissue is present.

In discussing this approach, the claims and the evidence supporting those claims are in agreement and the dentist can be confident that deviation from those claims will not occur.

Regard, Barry
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Re: Validating Endodontic Concepts

Postby ASHOK on Sun May 21, 2017 3:28 am

Hi Dr.Barry, greetings. Beautiful explanation as usual. I totally agree with you. Iam really fortunate that i came across with you as my Endo mentor and to your EDS system in my very beginning  days of practice and since after incorporating your technique, no looking back, its almost 10 yrs now. After observing so many glamorous adds on different cleaning and obturating systems in the present market, i really sometimes laugh and tell my friends that this glamour is not at all required to do a good endo. Why are they making endo procedure so complex , why cant they follow KISS principal.

Its my humble opinion to all the readers in this forum, whether new or old members , never doubt about EDS system and Dr.Barry's teaching, he is one of the finest and practical teacher i have ever met, who is really passionate about what he is doing. He is always open to challenges and he  always accepts your points if you are right, which is a very rare character which we dont usually find in this present business oriented  teaching faculty.

Dr.Barry , we are all really fortunate to have you as our endo teacher, i really doubt, at your age probably i will be sitting in a old age home, with out doing anything, lol. Keep inspiring us. Warm regards, Ashok.
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Re: Validating Endodontic Concepts

Postby BarryMusikant on Wed May 31, 2017 8:24 am

Dear Ashok,

You are too kind. That you feel this way inspires me to keep fighting the good fight. This coming January, I will be teaching endodontics at the new Touro dental school in New York state. I was asked to create the program because the executive director of the school learned the SafeSider technique years ago and said, "it changed his life." This is the technique he wants his students to learn. Quite miraculous considering the impact large amounts of corporate money have in administrative decision making today. From this platform, I hope to extend the rational for our alternative approach and broaden the discussion of just what constitutes the most effective procedures from the perspective of the tooth's safety and long term success.

Thank you for always being there with feedback, advice and personal warmth.

Warmest regards, Barry
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