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Dr. Schröder, what defines a truly good endodontic treatment for you today?
More than 20 years ago, endodontics in dentistry was primarily a craft. The real game changer for me came in 2010 – involuntarily. Due to the eruption of the Eyjafjallajökull volcano, a colleague and I were stranded at Frankfurt Airport. We suddenly had a lot of time and spent hours discussing endodontics. He said back then: “Three-dimensional diagnostics will change everything.” And that is exactly what happened.

With a CBCT (cone beam computed tomography), I mentally carry out the treatment before I even touch an instrument. I know which of the four canals I will approach first and where a bifurcation awaits me in the middle third.

So you already see the tooth in front of you?
Absolutely. I have a strong visual memory. In the past, I compared teeth with similar anatomy in my mind. Today, I no longer need that mental bridge – I see it in the CBCT image.
For upper anterior teeth without trauma, I do not need a CBCT. But for premolars and molars, it is essential for me. The 3D imaging of X-ray systems has made dental treatments extremely predictable. Surprises have become rare.

In Düsseldorf, you work with the Veraviewepocs 3D R100 from MORITA?
Yes. I was already familiar with the high quality of the Veraviewepocs 3D R100 2D/3D combination X-ray system from my professional experience. When the old unit in Düsseldorf literally gave up the ghost, the decision was made quickly. One week later, the Veraviewepocs 3D R100 was installed in the practice. Since then, our understanding has changed. We produce significantly better images, and everyone recognizes the gain in information. X-ray diagnostics influence our entire treatment concept.

Let’s move on to preparation. You work with three endodontic motors in parallel. Why?
It’s quite simple: while I am working with one endodontic motor, my assistant prepares the next one. I stay at the microscope, my focus remains on the tooth. That may sound trivial, but it makes an enormous difference to the workflow.

I use the Tri Auto ZX2+ (endodontic motor with integrated apex locator) from Morita – I already tested it as a prototype before its market launch in 2023. And my Tri Auto ZX2 (the predecessor model, editor’s note) is still running with its original motor head. The only thing I have to do is recharge it regularly. I have never had to replace the battery. Not once. In each device, I have stored my preferred settings. In most cases, I work in clockwise rotation with a defined torque. But I can switch at any time.

Many endodontic motors offer “reciprocal” motion patterns. What makes the Tri Auto ZX2+ with its OGP2 mode different for you?
Translated, reciprocal motion in endodontics is nothing more than, for example, “X+1 steps forward and one step back.” In the end, it remains a forward movement. MORITA’s OGP2 works differently. This motion pattern breaks down a circular movement into individual sequences and never allows more than 360 degrees in one direction.
The basic principle – cutting and relieving – increases safety and significantly minimizes the risk of tip lock. There is no safer movement in the root canal than this. For beginners, it is like a driver assistance system.

You like to compare this to a sports car.
Yes. You can drive a sports car with driver assistance systems in a relaxed way through the city. Or you can switch everything off and drive on the Nürburgring Nordschleife (racing course in Germany). Both are possible – what matters is what you personally can handle. If I want maximum efficiency, I work with a mode in which I define myself at which torque the safety function intervenes. Then the responsibility lies in my hands. If I am dealing with complex anatomies, I choose the OGP2 mode.

Despite the working length measurement integrated in the Tri Auto ZX2+, you still use a separate apex locator. Why?
I always explain to my patients: the apex locator is like parking distance control for the dentist. The endodontic motor offers me the option of parallel measurement, and in selected cases I gladly use that. However, there are situations in which measurement during endodontic preparation becomes difficult despite sophisticated measurement systems.

For example, when I have to go through a metal crown to perform root canal treatment. In that case, the file comes into contact with the irrigating solution, and the measuring current flows via the file into the solution, back via the metal crown to the gingiva. The result is incorrect measurements. To avoid this, I would have to reduce the volume of my irrigant in the pulp chamber down to the level of the canal orifice.

That is why I generally prefer to determine the working length manually under the driest possible conditions using the Root ZX3 apex locator from Morita. Only when I am certain is the length transferred to the files. With other devices, I have experienced cases where you advance the file by three or four tenths of a millimeter and nothing changes on the apex locator display. That is uncomfortable. With the Root ZX3, that does not happen. You have many fine intermediate steps – 40 bars on the display. To be honest, I only really look when the device starts beeping.

You also use EndoWave files, which promise greater safety. What has been your experience?
These endodontic files appear almost “pre-twisted,” are blunt at the tip, and behave in a very controlled manner. In combination with a safe motion pattern, this creates a clean glide path with minimal dentin removal. I therefore use them primarily in severely and multiplanarly curved canals. Apart from that, no experienced endodontist works with just one system. Anatomies vary. You need options – and a setup that supports them. For me, EndoWave files are part of that setup.

What is your conclusion as a dental professional?
Technology does not replace experience. But it expands enormously. For me, predictability arises from three things: precise 3D diagnostics, a flexibly adjustable preparation system, and reliable working length measurement. If I know what to expect – and my instrument does exactly what I want – then endodontics becomes predictable.

Dear Dr. Schröder, thank you very much for the insights into your workflows.