Why different endo files have a different “feel”

The One Endo file's cutting edge extends through its tip.

The One Endo file’s cutting edge extends through its tip allowing it to cut very efficiently. This efficiency, however, may be perceived as having an “aggressive feel”.

Endodontic files basically have three functions: forming a dentinal chip, dislodging the chip, and transporting the chip from an area of file engagement to an area of file disengagement.

A file may have a smooth feel when the blade is burnishing more than cutting, or when the flutes are compacted with debris. Using a “smooth” file usually requires a heavier touch or more pressure for advancement into the canal. Often this feel is confused as an attribute of a more effective file. In fact, the greater pressure required for advancement into the canal causes greater torsion stress that results in a greater propensity for failure compared to more efficient files.

Sharper more efficient files may have a rougher, scratchier feel than that of less efficient files. This is due to the formation of greater dentinal chips. These files require a lighter touch or less pressure for advancement to achieve the same results as less efficient files.

Often when one transitions from using a less efficient file to a more efficient file they have the tendency to use the same force as was required for the less efficient. Greater pressure can result in the formation a larger dentinal chips than can be easily removed and result in unnecessary excessive torsion stress.

Our extensive testing has consistently indicated that applying the following considerations will maximize efficiency and minimize risks:

  • Advance into the canal using no more pressure than was required to advance the first 1mm.
  • Engage no more than 6mm of a file if it is engaged in a curvature (the exception would be a size 20-.02 or smaller).
  • Advance a file into the canal with no more than 1mm increments with insertion/withdrawal motions.
  • Advancement into the canal should be able to occur at a rate of approximately 0.5mm/s without increasing the pressure of insertion.
  • Withdrawing at a rate greater than the rate of insertion improves debris removal.
  • Follow the use of one file with a file having a different taper.

What does progressive flexibility for the One Endo file mean?

Heat treated One Endo files are distinguished by a golden coloration.

In short, progressive flexibility means the flexibility increases as the need for flexibility increases. This is in contrast to the all or nothing approach of other brands. Flexibility of a file can be increased by the following means:

  1. Increase the depth of grooves. However, increasing the depth of flutes can make the instrument more vulnerable to torsional failure, particularly if applied to all file sizes.
  2. Increase the number of spirals. Yet, increasing the number of spirals has two consequences: the file has a greater tendency to screw-in, and debris has a greater distance to travel causing more abrasion and torsional stress.
  3. Apply heat treatment. However, heat treatment usually means decreasing the file’s resistance to torsional stress. Some manufacturers claim that their heat treatment  process actually enhances or has no effect on the file’s resistance to torsion stress. These claims are usually justified by measuring only the number of turns of rotation a file can be twisted before failure without consideration for peak torsion (greatest amount) the file can resist.

For virtually all cases, increasing flexibility decreases a file’s resistance to torsional failure. On the other hand, once the file has adequate resistance to torsional failure due to size, greater cross-sectional mass or flute design, the file’s flexibility can be increased by any or all of the means listed above progressively to enhance the file’s performance. The objective of the One Endo file series is to balance the need for flexibility with the need for torsional resistance. You will notice that One Endo files size 35 and larger are heat treated. The exception is size 35 .04/.06 in which its flexibility is increased by increasing flute depth. File size 55 .04/06 is heat treated to a greater degree to provide the needed flexibility for this large size.

Resistance to Change: What keeps you from leaping ahead?

Are dentists really, as the cliche goes, the most resistant to change? I contend that they change when change is worthwhile. So, what does it take for you to embrace changing endodontic files? Math can affirm that saving just 5 minutes a case can amount to 10-25 days a year of additional income or days off, not to mention the other benefits of efficiency. Even if these savings are validated, resistance to change could be influenced by many factors. Let’s consider some of the usual suspects:

  • You resist change because you feel you will not be able to make the transition easily.
    • Changing the instruments you use on a daily basis is a daunting prospect, especially when it means having to change your technique. While there are basic considerations to address within any technique to maximize its effectiveness, the One Endo File can be used with ANY technique to achieve better results. Also, It can even be used with a reciprocating handpeice as long as its clockwise angle of rotation is greater than that of its counterclockwise rotation. Objection over-ruled?
  • You resist change because you feel you have insufficient information.
    • NanoEndo provides you the opportunity to view side-by-side testing to measure the efficacy, efficiency and stresses of the file you are using with a comparable One Endo file. This is accomplished by using a computerized clinical simulator with precise prescribed movements. Objection over-ruled?
  • You resist change because you feel you believe the current way of doing things works well.
    • I have always identified with a quote from Henry Ford who said, “If I’d asked people what they wanted, they would have told me – faster horses.” Subscribing to the idea that well enough is good enough guarantees that your development and attitude will stagnate. Only with change can you enjoy the benefits of expertise while realizing your full potential. Objection over-ruled?
  • You resist change because you are too invested in inventory.
    • Can you justify investing in new inventory when you already have old inventory? Progress always pays off. We are providing the opportunity to buy what is arguably the best endo file available at half price with no limits on quantity. This price-benefit of the One Endo file is without equal in the market place. But the clock is ticking, and at the end of this year we will end what we think is the best deal around: every time you order a pack, we’ll ship you another for free – plus free shipping on all orders! Objection over-ruled

Remember the quote from Churchill, “To improve is to change; to be perfect is to change often.” Our goal is perfection; the next step is yours. We look forward to serving you. Visit the NanoEndo Store.