Rollon Nadella and VDW: A Long-Standing Collaboration for the Precise Manufacturing of Root Canal Files

Root canal files are among the most crucial components of modern dentistry. Their manufacture requires high-performance materials and extreme precision. This case study examines how VDW – an endodontic pioneer with more than 150 years of expertise – designs and produces these instruments using custom-built machinery supported by Rollon Nadella’s high-accuracy needle thrust bearings.

© VDW

Most of us are familiar with the unmistakable sight and sound of instruments in a dentist’s office. While these tools often evoke varying degrees of apprehension, they are indispensable for modern dental hygiene and restorative care. What may appear to be simple, standardized instruments are in fact the result of complex engineering and manufacturing processes. Root canal files, for example, begin their life as NiTi wire blanks and undergo grinding, twisting, heat treatments, electropolishing, and surface coatings – procedures that transform raw metal into flexible, fracture‑resistant tools capable of navigating the tight geometry of root canals.

VDW has helped shape the evolution of root canal therapy for more than a century and a half. The history behind today’s VDW began in 1869, when C. W. Zipperer founded an endodontic company in Munich. More than a century later, in 1972, the Zipperer company joined forces with Antæos and Beutelrock to form Vereinigte Dentalwerke (VDW). This merger consolidated deep expertise in endodontics and gave rise to the VDW brand known today for delivering complete workflows for root canal therapy, from preparation through obturation.

Designing the machine behind the tool

To manufacture its root canal files, VDW designed a dedicated machine that embodies decades of specialized know‑how.

The process is both rapid and exceptionally precise. The machine takes in the metal blanks, grinds and machines them, performs optical control, applies a black coating to improve visibility and length marking accuracy, and outputs one finished file every three seconds.

Given the high forces involved in material removal and shaping, the machinery must guarantee extreme precision while maintaining compact dimensions and high load capacity. As Andreas Vogel, Manager Maintenance and Facility at VDW, explains: “Accuracy is pivotal. But any component within the machine also needs to be able to handle heavy loads and strong acceleration forces.”

Despite these significant mechanical challenges, the process must remain delicate enough not to damage or fracture the thin, flexible files.

The Rollon Nadella solution

To ensure the precise motion of the machining heads while meeting stringent requirements for load capacity, acceleration, and compactness, each VDW machine incorporates eight special needle bearings from Rollon Nadella, installed to support the movement of the grinding heads.

These bearings not only help ensure the necessary accuracy but also withstand the high acceleration forces generated by the production process. “The AX needle thrust bearing from the Rollon Nadella range was chosen for its high accuracy. The rolling elements of a thrust bearing are retained and guided in radial pockets within the cage. The cage itself is retained in relation to the plate by means of a steel ring. This assembly is easy to handle and install and provides high axial load capacity while occupying minimal space”, explains Stephan Schott, Industry Manager Medical at Rollon.

The Rollon® Nadella® AX needle thrust bearing.

Speed is also a crucial factor: the grinding phase in which the AX bearing is used lasts only one second, demanding a bearing solution that can withstand constant, rapid, repetitive motion without performance degradation.

A collaboration rooted in decades of trust

VDW’s collaboration with Nadella for this specific machine began in 2001, but the relationship predates that: earlier Nadella components were already used on predecessor machines built in 1986, one of which still remains in operation. This longevity demonstrates the consistent trust between the two companies.

“It’s been a very long-standing collaboration, for which we are satisfied,” says Ilker Karadeniz, Process Optimizer at VDW. “Such partnerships are essential not only for guaranteeing reliable production but also for supporting continuous improvement. Close collaboration enables rapid feedback loops, tailored engineering solutions, and confidence in long-term supply and performance”.

Today, VDW is testing a redesigned version of its manufacturing machine, a process expected to last one year. This testing phase underscores the importance of ongoing innovation, particularly in industries where micrometric precision and high reliability are non-negotiable. Continued collaboration ensures that as manufacturing processes evolve, the components that support them evolve as well.