TruNatomy: Respecting the root canal anatomy in narrow, severely curved, or long canals

By Dr Anna Lechner

Patients have expressed their desire to preserve the function and aesthetics of their teeth for a lifetime. Successful endodontic treatments also play a significant role in this. Dr Anna Lechner, endodontist from Darmstadt, Germany, uses three case studies to show the improvements in terms of simplicity, safety, and possibilities of dentin preservation gained by using the new file system from Dentsply Sirona, TruNatomy.

Almost seven million root canal treatments are billed in Germany every year, and endodontics was the main topic at the latest German Dentists’ Conference in Berlin. Preserving tooth through endodontic treatment plays an important role in dentistry and is firmly anchored in the minds of dentists.

Over the past few years, there have been numerous studies addressing the clinical success of root canal treatments. Back in 2004, Friedman et al. published a study in which they certified that teeth without a periapical lesion had 92% to 98% chance of success, while teeth with a periapical lesion had an expected success rate of 74% to 86%.

In 2010, Ng et al. reported a success rate of 93% after four to five years, and a success rate of 87% after eight to 10 years. Gernhardt et al. showed in a review that “complete and safe preparation as well as successful management of the canal system infection by a maximum reduction in the bacterial count” are primarily crucial for this success, in addition to factors such as defect size, tooth type, and post-endodontic restoration.

I have specialised in this topic in my practice, where I had my 20th anniversary last year. I deal almost exclusively with patients who have endodontic issues. This is also why colleagues refer their patients to my practice.

We strongly believe that tooth preservation offers the best possibility of maintaining the existing physiological basis for preserving the natural chewing function. This is why it is important to preserve every tooth, and this takes priority over all other solutions. As specialists, we also check on a regular basis which modern instruments and materials can help make our treatments even more successful.


Generally speaking, we as dentists remain loyal to tried-and-tested systems. We are reluctant to switch instruments and materials because there is always some uncertainty as to whether others work just as well or whether they are also easy to use.

I personally like sharing experiences with colleagues and am happy to benefit from others’ experiences. But I am also someone who likes to try out new things – after all, there have been a number of recent improvements in endodontic instruments. One such new concept is TruNatomy from Dentsply Sirona, which was presented at the IDS 2019. This is a complete treatment solution, from Orifice Modifier to obturation, with great importance attached to the preservation of pericervical dentin. The latter is decisive for the stability of a tooth after root canal treatment.

The name TruNatomy is derived from the design of the files, which is based on the respect and preservation of the natural root canal anatomy, and therefore the tooth. The idea appealed to me, so I decided to test it out in my practice. The first impressions have already been positive; these are instruments that feel good in your hand. You can feel how the file moves in the canal, both during manual and machine use.

I am familiar with systems that work in an extremely extensive way and make removal feel “jerky”. This is not the case here. The files move in the canal quietly without the user having to apply any particular pressure. The file system is especially useful under difficult conditions, such as with obliterated, severely curved, or even very long root canals. TruNatomy files offer more minimally invasive access to the cavity because their high flexibility makes the files resilient.

Even more important to me is the cutting ability, with TruNatomy offering much more than the systems that I usually, and also quite successfully, work with. This is a very important function for narrow canals – it is difficult to remove debris under obliterated conditions, and the possibility for irrigation is limited.

To avoid blocking the canal during preparation, the cutting ability must be good enough to ensure removal at all times. Another important factor, especially for curved canals, is the right conicity of the files. This ensures that we can access up to the apical area, where we can then irrigate.

TruNatomy’s paper points and gutta-percha points are also adapted to this conicity, making this treatment step much easier. Furthermore, TruNatomy files have proven to be extremely robust. There are already some initial studies that have tested the files in terms of their cyclic fatigue resistance.

Both Rhyahi et al.5 and Elnaghy et al.6 was impressed by the cyclic fatigue resistance of the TruNatomy files. This enables the files to improve patient safety with a reduced risk of file breakage compared to other systems.

The TruNatomy files have been an integral part of my practice’s instrument portfolio for about one year. They give me real added value for narrow and long root canals. The following cases provide examples of this.

Continue reading here. Published in Dental Asia March/April 2021 issue.

About the Author:

Dr Anna Lechner is a specialist in endodontics who completed her studies at the Ruprecht- Karl University in Heidelberg, Germany. Over the years, she attended various courses in endodontics, traumatology, laser, and DVT. At present, she runs a private practice specialising in endodontics and also conducts lectures in the same field. She is a certified member of the German Society for Endodontology and Traumatology (DGET) and Association of German Certified Endodontologists (VDZE).