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Inside Dentistry
July 2014
Volume 10, Issue 7

Clinical Use of the ESX File System

New instrumentation and protocols for simple, efficient procedures

Allen Ali Nasseh, DDS, MMSc

Endodontic instrumentation continues to improve through the introduction of new instruments and techniques. There are currently multiple file systems on the market, each with a unique way of achieving canal instrumentation. The new endodontic nickel-titanium (NiTi) rotary instrumentation system ESX® (Brasseler USA, is an advanced rotary file system that aims to improve two specific instrumentation challenges: system simplicity and cutting efficiency using fewer files.

In addition, this robust instrumentation system is complemented by an effective, simple, and inexpensive obturation system.1,2 This combination of a simple and efficient instrumentation and obturation system makes predictable endodontic therapy accessible to all clinicians performing root canal therapy.


ESX System Features

The ESX System was inspired by the original EndoSequence® system (Brasseler USA).3-5 The core design features of EndoSequence files, namely the triangular cross section, their patented asymmetrical Alternating Contact Points™ (ACP), and the electropolished6 NiTi metal wire, remain the same with the ESX (Figure 1). Both file systems use a recommended speed of 500 to 600 rpm and a torque control value of 1.8 to 2.2 Ncm.

There are three significant differences between the two file systems:

The ESX file has incorporated a new, patented BT-Tip™ (booster tip) (Figure 2), which helps guide the file while simultaneously reducing canal ledging.

The use of a unique operator motion called Single Stroke and Clean™ technique, which drastically reduces torque exerted on each file.

A more efficient protocol requiring fewer files to achieve the same results.

The third feature is only possible since the ESX file takes full advantage of the first two features. The combination of the BT-Tip and the Single Stroke and Clean motion allows the ESX file and its associated technique to be more efficient than its predecessor EndoSequence File. Let’s briefly discuss these two main features.

The BT-Tip is present on all four ESX Finishing Files (25, 35, 45, 55, all in 0.04 taper). The presence of a BT-Tip is designated on ESX Files by a notch on the handle (Figure 3). The BT-Tip uses flat transition angles from the rounded non-cutting tip to advance to the triangular shank, thus creating six cutting edges and a narrower tip. This change in tip design creates a doubling of the cutting edges at the tip. This combination helps create a guiding element to the tip with the benefit of reduced potential for ledging. This guiding tip and new theory of an operator file motion based on the chip space (Single Stroke and Clean technique) allow the clinician to move between greater incremental file sizes, reducing the number of files required to instrument any given root canal.

The Single Stroke and Clean operator motion recommended for each ESX file also significantly reduces the torque exerted on each file in the series. The technique involves using each ESX rotary file for one engagement and filling of the flutes, followed by its immediate removal and cleaning of the file. The theory is based on removing the accumulated debris in the file’s chip space after each stroke, clearing the file for unrestricted cutting during the next ensuing stroke. This single stroke action followed by wiping is recommended on every file used in this system: Scouting Files, Expeditor™, and Finishing Files. The combination of the BT-Tip and Single Stroke and Clean technique allows clinicians to forge a simpler and more efficient basic protocol for the use of ESX Files compared with their predecessors.

Choosing a Protocol

The Basic ESX File System (Figure 3) consists of a 15/.05 Expeditor, and Finishing Files 25, 35, 45, and 55/.04. The protocol for the Basic ESX instrumentation system is to hand instrument the canal to the full working length to a size 15/.02 file, and then to use the Expeditor file (15/.05) down to the same length using the SSC motion. Depending on the level of engagement experienced by the Expeditor on its journey down to length, a decision is made about which finishing file is appropriate. If significant engagement is met, then a size 25 Finishing File is used to the same length using the Single Stroke and Clean motion. A size 35/.04 is used as the Master Finishing File when the Expeditor experiences moderate engagement to length, and a size 45 is used when the Expeditor experienced minimal engagement to length. A size 55 is also provided for cases where the operator feels inadequate cleaning after the size 45 Finishing File has reached the apex.

Following instrumentation, irrigation, and disinfection, matching size ESX BC (bioceramic)-coated gutta-percha cones are recommended along with hydraulic condensation using BC Sealer1,2 (Brasseler USA) to obturate the root canal and achieve a seal.

The Basic ESX protocol will address most routine clinical cases. However, with more challenging cases with significant curvatures or calcifications (when achieving a size 15/.02 before the use of the Expeditor is difficult) an Advanced ESX protocol is recommended. The advanced protocol uses three additional files before using the Expeditor (Figure 4). The ESX Orifice Opener (20/.08) and two ESX Scouting Files (15/.04 and 15/.02), alone or with hand instrumentation to sizes 8 or 10, will do some “pre-Expeditor” instrumentation to achieve the required 15/.02 shape to working length (before employment of the Expeditor).

Final Thought

The simple and logical progression of the Basic and Advanced ESX instrumentation protocols is a product of the superior manufacturing quality of the established EndoSequence File, along with the addition of two new features: advanced BT-Tip Technology and a new, logical, and safe Single Stroke and Clean operator motion that makes the new ESX File System both efficient and simple for clinicians performing root canal therapy with basic or advanced protocol (Figure 5 and Figure 6).


1. Koch KA, Brave DG, Nasseh AA. Bioceramic technology: closing the endo-restorative circle, Part I. Dent Today. 2010;29(2):100-105.

2. Koch KA, Brave GD, Nasseh AA. Bioceramic technology: closing the endo-restorative circle, part 2. Dent Today. 2010;29(3):98, 100, 102-105.

3. Koch KA, Brave DG. Real World Endo Sequence File. Dent Clin North Am. 2004;48(1):159-182.

4. Koch K, Brave D. The EndoSequence file: a guide to clinical use. Compend Contin Educ Dent. 2004;

5. Koch K, Brave D. Endodontic synchronicity. Compend Contin Educ Dent. 2005;26(3):218, 220-224.

6. Anderson ME, Price JW, Parashos P. Fracture resistance of electropolished rotary nickel-titanium endodontic instruments. J Endod. 2007;33(10):1212-1216.

About the Author

Allen Ali Nasseh, DDS, MMSc
President, RealWorldEndo™
Clinical Instructor
Department of Restorative Dentistry and Biomaterial Sciences
Harvard University School of Dental Medicine
Boston, Massachusetts
Private Practice
Boston, Massachusetts

For more information, contact:

Brasseler USA Dental

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