WANT to talk about a new feature on the Web where we are going to do a tremendous amount of writing. I have been puzzled for a long time about exactly what all our teachings constitute and how to sum them all up in one word. It dawned on me that what we are really trying to teach is rational endodontics, a common-sense way to perform challenging tasks that should not be made more challenging by systems that introduce greater insecurities. From my early experiences with rotary NiTi, I appreciated the greater tapered shaping done with an engine that reduced hand fatigue, but I was never comfortable with the increased incidence of separated instruments and all the precautions that had to be taken to reduce that frequency of incidence.
Since we invent things that make the lives of dentists easier and we are the first beneficiaries of those inventions, we were highly motivated to gain the advantages of rotary NiTi while eliminating its obvious disadvantages. This search led to some insights that have been validated more and more over the years since we successfully incorporated them. Below is a list of the rational insights we have gained over the years, with a small explanation of their rationality when necessary.
- K-reamers are superior to k-files. K-files have horizontal flutes and are most often used in a watch-winding motion. When a horizontal motion is combined with horizontal flutes, the result is engagement and disengagement with minimal circumferential cutting. K-reamers, which have more vertically oriented flutes, engage less and cut more efficiently when the watch-winding motion is used.
- Relieved k-reamers are superior to non-relieved k-reamers and far superior to non-relieved k-files.
- When we say that k-reamers are superior, we mean that they have the ability to negotiate apically with the least resistance possible, producing minimal stress to the root and to the instruments.
- A relieved k-reamer is more flexible than a non-relieved k-reamer and far more flexible than a non-relieved k-file.
- A relieved k-reamer can best afford a cutting tip because it offers the best tactile perception of what the tip of the instrument is encountering when negotiating apically.
- The relieved reamers are all used in a 30-degree reciprocating handpiece.
- A 30-degree reciprocating handpiece virtually eliminates the torsional stress and cyclic fatigue associated with rotary NiTi separations.
- All the stainless steel reamers that constitute our sequence can be prebent and placed into the most curved canals in the correct orientation to the initiation of the curve and then reconnected to the 30-degree reciprocating handpiece, producing distortion-free shaping even when enlarged to a 45, 50, or 60.
- The bidirectional spiral of EZ-Fill® cement thoroughly coats the canal walls, allowing a well-coated single point to create a three-dimensional fill.
- Placed at room temperature, the cement and the gutta percha warm to body temperature, expanding about 1.75 percent in the process. This expansion contrasts with the 4–5 percent shrinkage that occurs with every thermoplastic system.
- The epoxy-resin cement used in obturation has better flow at room temperature than thermoplasticized gutta percha has, making it more likely to fill all the nooks and crannies of the root canal system.
- The epoxy-resin cement binds chemically and physically to the gutta percha and the dentin in the walls of the canal.
- The procedures necessary to properly shape and obturate with our system establish a wide window of success. They virtually eliminate the risk of breaking instruments or expressing gutta percha beyond the apex of the canal.
- The cost of instrumentation and obturation is dramatically less than the cost of rotary NiTi and thermoplastic obturation, and the system does not produce any of the anxiety associated with these techniques.
You probably have read about most of these advantages in previous issues of Endo-Mail, but we are now going to describe them in detail, using as examples many cases in which the design features listed above make for excellence in endodontics. In addition, we are going to critically review as many articles written by advocates of rotary NiTi and thermoplastic obturation as we possibly can, to analyze the strengths and weaknesses of their viewpoints. For too long, the major companies have been able to monopolize the education of dentists, starting when they are students in the dental schools and later by controlling most of the content that gets into the dental trade magazines as well as the major meetings. This cannot be stopped. Their economic clout is overwhelming. However, they cannot control the content on the internet—at least not presently—and there, where playing field is level, our viewpoints can be judged on the basis of their common sense rather than money directed to the magazines, the major meetings, and the dental schools.
We have a very active educational program both in the United States and abroad, and we will keep you all informed of the dates and locations of our courses and presentations so that you can take advantage of at least an introductory hands-on experience of rational common-sense techniques. It should almost go unsaid, but when techniques are rational, learning them becomes far simpler because of the common-sense logic backing them up. What you experience is a virtuous cycle of learning that continually reinforces itself with more and more experience.
I cannot help adding that the traction our message has gotten to date is sufficient evidence that those who claim to be most concerned about the welfare of our profession should by all means open up the gates to a far wider set of opinions even though it will not be in the best commercial interests of the big companies. That would be a sure way to show that what they preach is in line with their actions.
Some of you may be old enough to remember President Eisenhower’s farewell address, in which he warned us of the military-industrial complex that led to—among other things—the $600 toilet seat as well as the $200 hammer. Today we have an educational-industrial complex that has become no less efficient at jacking up prices after creating their monopoly. Our goal is to inform more and more dentists of all their options so that they can make truly informed decisions. Our main avenue for doing this is the Internet, since it is the only medium devoid—to date—of monopolistic controls and high costs of entry.
I am confident that we will be successful at this because our approach is good for dentists and because if people are well informed most will act rationally, with common sense, and come to the right decision for themselves, which we believe is exactly where we want you to go.
January - March 2008
If people are well informed, most will act rationally, with common sense, and come to the right decision for themselves.