EndoTech NZ

FlexiIon - next generation heat technology.

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01 // Flexible response

Safety First

Canal anatomy is rarely straight. FlexION brings amazing tactile awareness

02 // Working control

Perfect Shaping

Coronal cutting is class leading

03 // Clinical system

Simplicity

FlexION metallurgy allows for simplicity — three file systems.

File Essentials

WORKING SECTION
FlexION file showing the working section, marked shank and rubber stopper
CONTROLLED RESPONSE

[ 03 ] Technology architecture

FlexION decoded.

FlexION brings controlled flexibility and reliable shape recovery together for clinical shaping. Advanced NiTi metallurgy supports our focus on premium performance, single-use file systems, and exceptional value. Explore the file systems ↗

FLEX

Scroll to explore the science Right-click to zoom

ION
Artistic lattice of twinned martensite with alternating crystal orientations.
Twinned martensite · artwork Artistic representation

Not a measured atomic structure.

The science behind the structures. Models show atoms rearrange between cubic austenite and monoclinic martensite.

FlexION brings controlled flexibility and reliable shape recovery together for clinical shaping performance - Advancing Endodontic Safety through Advanced Metallurgy

FlexION / File essentials

01 / Temperature & metal

Advanced NiTi
metallurgy

A file warms up inside the tooth.

NiTi is an alloy of nickel and titanium. Its atoms can change arrangement while the metal stays solid. These different arrangements, called phases, affect how easily the file bends.

Martensite is easier to bend. Austenite is generally stiffer and tends to spring back. Heat treatment changes the temperatures at which the metal moves between phases. Some files also pass through an intermediate R-phase.

Af means austenite finish temperature: the point at which the change to austenite finishes during heating. An Af above body temperature can help retain martensite or R-phase inside the metal. Some files lose cyclic-fatigue resistance as their austenite proportion increases at body temperature. In an apical curve, breakage risk also depends on the file design, curve tightness, and technique.

Why Af is only part of the explanation

Af above 37°C does not mean a file is entirely martensitic at 37°C. The full heating and cooling history, applied stress, and file design also matter. Austenitic NiTi can still flex through stress-induced transformation. Af is not a stand-alone safety rating.

Read the research: Arias et al., 2018 ↗ · Kasuga et al., 2023 ↗

≈37°C

Body temperature.
The reference for testing.

FlexION Af Temperature to confirm
On the bench~22°C
Body reference~37°C
Heating completesAf
Schematic only. FlexION’s Af temperature is awaiting confirmation; marker placement is not a measured value. Irrigation and treatment conditions can change the temperature inside a canal.

FlexION in the apical 2 mm

A bend test at room temperature may not describe how the same file behaves clinically at 37°C — body temperature.

File manufacture must account for how the last 2 mm of a nickel-titanium file behaves deep inside a root canal, particularly through severe apical curvatures. As the file warms towards body temperature, its balance of crystallographic phases can change.

In some NiTi files, an increased proportion of austenite at body temperature is associated with greater stiffness and lower cyclic-fatigue resistance. Repeated bending in a tight curve can then lead to fatigue cracking and file separation. The risk also depends on file geometry, loading, and technique.

FlexION technology is designed with the aim of retaining martensite and R-phase at clinically relevant temperatures, to maintain flexibility when negotiating demanding apical anatomy.

02 / Bend & recovery

Controlled
flexibility

Less force to make the bend.

A flexible file needs less force to follow a curve. Its alloy, thickness, taper, and cross-section all affect that bending force. Heat treatment can reduce stiffness, but the finished file needs testing at a relevant temperature.

As a file rotates in a curve, the metal repeatedly stretches on one side and compresses on the other. Repeated loading can start a crack. This is cyclic fatigue.

Torsional overload is different: part of the file binds while the motor keeps turning. Greater flexibility or a longer fatigue life does not automatically mean greater resistance to twisting.

Download research references (PDF · 2 studies)

Endodontic file with a metal handle, red stopper, straight marked shank and curved gold cutting flutes. Guides show stretch outside a bend and compression inside it. Stretch Compress ENDODONTIC FILE
Outside of the bend Inside of the bend
File shown for illustration. The dashed guides mark the outside and inside of one bend, not measured strain. During rotation, each side repeatedly changes between tension and compression.

Bending fatigue and twisting overload are why most all files separate.

03 / The shape inside the tooth

Curved
canal anatomy

The tightness of the bend matters.

A root canal is a small passage inside the tooth. It can bend in more than one direction. A two-dimensional X-ray may hide a curve pointing toward or away from the viewer.

Two canals can turn through the same angle yet place different demands on a file. A tighter bend has a smaller radius of curvature, so the file bends more sharply over a shorter distance.

In Pruett and colleagues’ laboratory study, tighter curves and larger instruments shortened fatigue life. Files broke around the point of greatest bending. That point depends on the canal and is not always at the tip.

Shaping aims to preserve the canal’s original route while making space for cleaning. Flexibility helps, but anatomy, file selection, and technique still matter. Follow the file system’s instructions for use.

Read the research: Pruett et al., 1997 ↗ · Balani et al., 2015 ↗

Ask about our amazing Next Gen Motor
Gentle turn Larger radius

Little danger

Tight turn Smaller radius

High danger for normal files

Both schematic paths turn through 90°. The tighter path concentrates bending into a shorter length. These are explanatory shapes, not clinical measurements.

Must visualize the 3D canal curvature — sometimes hidden in the ML plane — especially the MB canal in lower molars and the MB roots of uppers.

Explore the file systems ↗
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