Cents and sensibility

X-ray taken by Dr. HB Johnson circa 1939 (courtesy Dr. Tom McDonald, Atlanta GA)

X-ray taken by Dr. HB Johnson circa 1939 (courtesy Dr. Tom McDonald, Atlanta GA)

When preparing a root canal, there seems to be nothing that can’t be achieved by a skilled endodontist. In the right hands, virtually any root canal can be prepared with virtually any file or number of files. The very small curvature radius and large curvature angle in the featured x-ray illustrates the extraordinary skill for using carbon steel files in 1939 by Dr. H.B. Johnson, the individual that gave us the term “endodontics.”

Curiously, it is rare that a file is promoted today without an accompanying x-ray depicting an extraordinarily difficult case. Should we conclude then that all files will enable you to achieve ideal root canal preparations? We can eliminate almost all restrictions except for one, our inability to freeze time. Ahh… there’s the rub. Time is our most valuable commodity.

Many years ago, a clever sales rep showed me a time saving formula demonstrating the annual money savings that a very expensive digital x-ray device would provide before convincing me to buy what turned out to be the very first digital x-ray device sold in the US. Ever since, that formula has continuously convinced me that penny-pinching at the expense of saving time isn’t really saving money at all. It’s no different with endodontic files. Consider that by saving 10 minutes/patient with each of 6 cases/day for 200 days results in 5 weeks of chair time saved annually. That’s more than a month of additional production, vacation or whatever you like!

A file’s ability is not the issue. Rather, a file’s efficiency during performance is THE most important issues and our guiding objectives when designing NanoEndo files. Our results are extremely successful in this regard and our customers agree that NanoEndo’s highly efficient designs save them time and reduce risks during root canal preparations. See for yourself and review our comparisons with the files you are using now or give us a call (844.ONE.FILE) to learn more. Remember lost time can never found.

Is scientific hype replacing scientific evidence?



**Watch this VIDEO to see a brief summary on how results from our testing of file performance differs from conventional testing of flexibility and cyclic fatigue.**

Many endodontists have devoted a great amount of valuable time to endodontic instrumentation research using scientific evidence in an attempt to convey useful information for the advancement of endodontics. Scientific evidence relies on comprehensive data and it is crucial for researchers to ensure that the data they collect is sufficiently inclusive to have relevance to actual clinical situations. When “scientific hype” reaches the point that it diminishes the value of scientific evidence, then practitioners need to be aware that insufficient information can have counterproductive consequences.

During scientific research it is not uncommon to encounter hype. Although somewhat frustrating, common hype is usually tolerated because claims are at least somewhat true. Even though the benefits of the claims are usually exaggerated, they are transparently limited in scope. An example of such a claim would be: “These files are faster, safer, and require fewer sizes.”

What is apparent to the dentist is the missing ‘compared to what’ or ‘under what circumstances’. Taken alone, these claims are obviously discounted as scientific evidence. Recently, however, a more insidious hype, one that uses insufficient and selective scientific testing, has lead to erroneous conclusions and created an opportunity for mistakes. This type of hype uses the convincing nature of inductive reasoning that is not so apparent, but may be easier to recognize once it’s broken down into logical propositions. Consider the following examples:

From a specific proposition such as:
A file’s greater resistance to cyclic fatigue is better than less resistance to cyclic fatigue.

To a general proposition:
Greatest resistance to cyclic fatigue results in the best file.

This particular general proposition has gained widespread acceptance and success in the promotion of endo files. One company claims, “700% greater fracture resistance compared to traditional NiTi files” without stating that the increased resistance to cyclic fatigue was accompanied by a reduction in the resistance to torsional stress, an essential component of resistance to failure. Another company uses resistance to cyclic fatigue as evidence for “unmatched strength”, “Off the charts Strength,” “Amazing strength means the confidence…,” and “Twice the strength, half the cost.”

The definition of strength within the context of metallurgy is the resistance to deformation. Now consider that the files described above distort with the least force of almost all, if not all, of the files on the market. All other factors being equal, increasing the resistance to cyclic fatigue is concurrent with a decrease in file strength and resistance to torsional stress. Unwinding is evidence of torsional stress. The question becomes, as long as the resistance to cyclic fatigue is adequate, why compromise by reducing the resistance to torsional failure?EdgeVsOneEndo_Graphs

There are certain features of science that give it a distinctive character as a mode of inquiry. Once that mode of inquiry is compromised, It is no longer valid science. When a company claims that its file will rotate over 600 seconds in a 90 degree curvature 3mm from its tip, and that capability is two times as long as a competitive file, does it make it a better file? If it does, does that mean a copper wire of the same diameter that will rotate 1,800 seconds is the better file? Actually, it only means that it has better resistance to cyclic fatigue in that particular circumstance with no evidence for superior performance. Besides, who lets a file rotate 600 seconds in a 90 degree curvature? Or even 10 seconds? Is there relevance to actual clinical situations?!

The ultimate goal for instrumentation advancement can be stated as, ‘maximizing efficiency and minimizing risks while accomplishing the preferred results.’ How effectively that goal is achieved is a measure of performance. My hope is that you will scrutinize all claims of advancement to the best of your ability. That especially pertains to any claims that I might make. Scrutiny is the hallmark of advancement.


Limiting Torsional Stress on Endodontic Files: Lubrication, Irrigation and/or Technique


I was recently asked if irrigation and lubrication influenced the stresses a file undergoes during instrumentation. Research that I carried out indicated irrigation and lubrication can reduce torque requirements by as much as 400% compared to rotating in a dry canal. However, one can see from the included chart that the amount of the file’s engagement can be as important as the lubricant itself in reducing torsional stress. Shorter strokes of insertion is more effective in reducing torsional stress than carrying the rotating file to greater depth into the canal with fewer insertions. When the rotating file becomes engaged for more than a very few millimeters, the interface of irrigation is reduced between the surface of the canal and the file and torsional stress increases.


The importance of engagement is illustrated. Quantec files were inserted in 1mm increments at 1mm/s with a depth of 8, 10, and 12mm. The torque recorder is an average of 6 files taken for each depth. Note minimum engagement can have approximately the same benefit as irrigation in reducing torque.

Conventional Research: Greater Value than Actuality?

Screen Shot 2015-11-09 at 9.08.49 AMAfter so many years of research, it is daunting to succumb to the realization that so much of my time was devoted to compiling conventional, or what could be considered useless, data for evaluating endodontic files. Someone once commented, “There is no ox so dumb as the orthodox.”

For instance let’s consider a file that is statically in the 50 percentile compared to other files in resistance to cyclic fatigue and also in the 50 percentile (50/50) in resistance to torsional failure. Research will reveal that files that are in the same percentiles can perform very differently. Compiled data for these percentiles might give little indication as to how a 60/40 percentile would perform  or a 40/60 percentile. Certainly a 100/? percentile can amount to little more than hype. There are too many other design differences to consider for extrapolating for conclusions.

My realization from the research I have experienced is, file features should only be considered file features with no indication of how the file will perform until performance itself is measured. Only then, should we attempt to explain the performance in terms of the file’s features. We can use the “ox“ depiction again to represent the paradox of Schrodinger’s cat; we have to see the results first to explain them and then our explanations might actually be very comprehensive.

Fortunately, we at NanoEndo have conducted literally 100s of file evaluations measuring performance, probably more than all other performance evaluations put together. And, fortunately, you do not have to depend on projections. NanoEndo files speak for themselves; their performance excels beyond comparison. We invite you to see for yourself.

NanoEndo and Stellar Studios Awarded Gold Communicator Award for nanoendo.com

NanoEndo is proud to announce its website, nanoendo.com, has been awarded a Gold Communicator Award from The Academy of Interactive and Visual Arts. The website was developed in conjuction with Stellar Studios, a multimedia marketing agency based in Johnson City, TN. The Gold Communicator Award falls within the Websites, Websites Visual Appeal category and recognizes nanoendo.com for its unique design characteristics and overall esthetic appeal.

“We really wanted to create something different that stands out from our competitors. My father and business partner, Dr. McSpadden, is distinguished as one of the world’s foremost endodontic file designers and he considers the One Endo file to be the best overall file design he’s ever seen. When we founded NanoEndo LLC to bring the One Endo file to market, I knew that our website would become the cornerstone of our efforts and I wanted its design to highlight the same uniqueness in thought and attention to detail evident in my dad’s instrument design. I have a long history of working with Stellar Studios to create award winning multimedia designs and it was a forgone conclusion that they would help us achieve our goals. Stellar Studios is an outstanding agency with tremendous talent and we are very fortunate to count them among our friends and partners.” – JT McSpadden, Chief Operating Officer, NanoEndo LLC

The Communicator Awards is the leading international awards program recognizing big ideas in marketing and communications. Founded two decades ago, The Communicator Awards receives over 6,000 entries from companies and agencies of all sizes, making it one of the largest awards of its kind in the world. The Communicator Awards is sanctioned and judged by the Academy of Interactive & Visual Arts, an invitation-only group consisting of top-tier professionals from acclaimed media, communications, advertising, creative and marketing firms. AIVA members include executives from organizations such as Airtype Studio, Big Spaceship, Conde Nast, Coach, Disney, The Ellen Degeneres Show, Estee Lauder, Fry Hammond Barr, Lockheed Martin, MTV Networks, Pitney Bowes, rabble+rouser, Sotheby’s Institute of Art, Time, Inc, Victoria’s Secret, Wired, and Yahoo!