Interpreting Research for Endodontic Instrumentation

IllusionBoxFileThere is an anecdote about a man having one foot in ice and the other in boiling water. In considering only the foot in ice the man is very cold. Considering the other foot only, the man is very hot. Statically speaking, on average, he is pretty comfortable. None of the three defined parameters can be interpreted in an objective and critical way to draw conclusions about his situation.

Albert Einstein said, ”Not everything that can be counted counts, and not everything that counts can be counted.” In other words for the endodontist, statistically significant or even a highly significant difference does not necessarily mean a clinically important finding.

Researchers should describe their results clearly, and in a manner that allows them to be critically interpreted to correctly assess their implications before drawing conclusions for treatment. Historically, endodontists have had to struggle with a recurring issue; that most research for endodontic instruments, is performed within very narrow parameters and without clearly defining the limitations or implications for drawing conclusions for their usefulness.

Nanoendo is making every effort to enable the endodontist to draw broader conclusions by using broader testing parameters and eliminating operator bias and capability within our research. We do this by using a computer controlled clinical simulator, our Endo File Evaluator. Its movements are exact and consistent. The Evaluator’s dependability means that its data and that the process NanoEndo employs to obtain results can be replicated. We understand that using a sophisticated computer does not necessarily deem a study valid for conclusions. However, we are committed on an unprecedented scale, to enabling the clinician to assess information and enhance his/her practice by continuously adding useful data for their review.

Furthermore, if there is a specific set of tests you would like to see carried out on our Endo File Evaluator, NanoEndo invites you to work with us to advance endodontics. To participate, submit your ideas and Request a Test.

Considerations for Initial Testing with NanoEndo’s Endo File Evaluator V2

We attempted to select parameters for our first round of testing endo files [Protocol = Advancement into canal (500rpm)] that would provide information relative to all file capabilities. Failure during testing does not necessarily indicate a file’s inferiority. For instance, a size 55–.06 taper is not an instrument we would ordinarily use as initial file for preparing a canal; however, we can obtain very useful information when a file is subjected to conditions that would cause failure. Knowing limitations can be just as useful as knowing capabilities particularly when comparing one file that is comparable in size to another: When debris remains intact rather than being broken-up as it is being channeled from the canal, greater abrasion occurs and the result is greater torsion.


This illustrates the need to break up the debris to reduce the resulting torsion. The smaller taper of the One Endo file accomplishes this function.


The 25-.06 Zeno file screwed into the canal, the blades engaged deeply in the canal wall and stalled the Endo File Evaluator due to excessive torsional force.

broken tip

The tip of a ProTaper Next file tip appears loose but broke 3mm from the tip. The cross section of this file is rectangular and only two corner blades (note arrow) are engaged. The reduced cross sectional area lacked the torsional strength to resist breakage. This illustrates the reason we incorporated the two tapers on the One Endo file.

Debris can become compacted in the flutes to the extent that the blades of the file cannot adequately become engaged into the canal wall and undue torsion stress results and cutting efficiency is reduced.

Debris can become compacted in the flutes to the extent that the blades of the file cannot adequately become engaged into the canal wall and undue torsion stress results and cutting efficiency is reduced.

Abrasion and inefficiency of cutting caused the bubbling of the plastic on the practice block canal wall due to torsional friction.

Abrasion and inefficiency of cutting caused the bubbling of the plastic on the practice block canal wall due to torsional friction.

A New Classification of Endo File Design

Dr. John T. McSpadden, DDS, accomplished practitioner, entrepreneur and inventor of endodontic instruments, announces the launch of his latest venture, NanoEndo LLC. Based in Chattanooga Tennessee, NanoEndo is introducing and marketing a completely new type endodontic file, with plans for introducing other file designs falling under his recently patented category of endodontic instruments.

In 1997, Dr. McSpadden designed a computer controlled endodontic file evaluator and conducted over 2,000 tests to determine key performance metrics for nearly every commercially available endodontic file. As Dr. McSpadden compiled data, he began writing what would ultimately serve as the foundational elements of his award winning book, Mastering Endodontic Instrumentation, published in 2007.

Since the book’s release, Dr. McSpadden constructed a second, more advanced, computer controlled endodontic file evaluator. “As I tested more and more files, the relationships between specific design elements and their performance became self-evident. Consequently, elements for an optimally designed file became apparent. I recognized the opportunity to create a totally new genre of file design, succeeded in obtaining a patent for it, and created the One Endo™ file, the first endodontic file to feature two different tapers side-by-side and designed entirely on evidence based criteria.” said McSpadden.

The formation of NanoEndo LLC originated from McSpadden’s desire to bring the One Endo™ file to market while simultaneously creating the most comprehensive informational resource on endodontic file design and performance available to anyone with an Internet connection. JT McSpadden, Dr. McSpadden’s son and business partner, stated, “My dad’s visions and ventures have never been simple – NanoEndo is no exception; it’s about much more than simply marketing a new endodontic file. He really wanted to create a means by which anyone could advance their practice by taking full advantage of file designs informed by his decades of research. It’s why he literally wrote the book on instrumentation, and why he called upon my expertise in digital multimedia to create” will function as the central marketplace for purchasing the One Endo™ file and other assorted products. Additionally, will feature a section dedicated entirely to sharing results from the Endo File Evaluator ( Results of research will be available to view through info-graphics displayed alongside video clips of respective tests as they occurred.