Product Evaluation

Every dentist gradually develops muscle memory over many years of performing repeated dental procedures. However, dealing with complex root canal anatomies can trouble even the most experienced hands in endodontics, which rely on both their honed skills as well as the precision and performance of the instruments they use.

Designed with a proprietary heat-treatment for high cutting efficiency and resistance to cyclic fatigue and file separation, Kerr Dental’s ZenFlex CM nickel-titanium (NiTi) rotary fi les demonstrate a similar form of learned behavior—their advanced controlled memory enables them to naturally adapt to curved and narrow canals with ease.

Dr. Jason Ingber’s recent experience with these files truly put their controlled memory to the test, especially in challenging endodontic procedures.

“I was able to properly negotiate to working length quicker and easier due to the flexibility and taper of the fi les, and complete the cases perfectly,” he said, further describing ZenFlex CM as “a simple fi le system with predictable results.”

File Flexibility and Cutting Efficiency

ZenFlex CM files feature a unique triangular cross-section that yields excellent flexibility for up to 90º curves, which allows clinicians to effectively reach the full working length of complex root canal anatomies while enhancing overall clinical efficiency.

“I think this is the most flexible file I have ever tried,” said Dr. Ryan McNeil, and Dr. Nicholas Nicosia agreed, adding that he could not believe the flexibility and ease of use of the fi les. Dr. Patrick Wells said, “I have been using ZenFlex fi les, and I found the CM fi les cut faster.” Dr. Oluwakayode Olowoyo said, “It’s a very simple, efficient system.”

 Looking for “a faster way to do endo with less worry about breaking a fi le,” Dr. John Jackfert found he “could obturate canals with more efficiency because the fi les were cutting efficiently, and I had fewer worries about breaking one in-side the canal due to their flexural strength.” He continued, “I loved the fi le flexibility and their ability to return to the original profile after being removed from the canals,” also noting that the ZenFlex CM fi les “could adapt to any curves in the canals of the tooth.”

Dr. Gary Henkel liked the flexibility of the fi les best, and Dr. Grace Chu said she would recommend ZenFlex CM fi les because of their “good flexibility,” which she said is “great for dilacerated roots.” Dr. Ingber noted, “The fi les were very flexible and able to negotiate canals conservatively.”

Range of Files to Navigate the Canals

Available in both .04 and .06 configurations in a range of fi le sizes and lengths, ZenFlex CM fi les can be prebent for improved adaptability and easier access to root canals—even in the most challenging cases. This contributes to more streamlined endodontic care and optimized treatment outcomes.

“These fi les effectively and conservatively navigate to the apex,” Dr. Nicosia said. “It was amazing how effectively they navigated the canal and easily reached the apex consistently without failure.”

“I was able to prebend the fi le a bit for easier access or insertion into the canal orifice,” Dr. McNeil added. Dr. Shari Mathew liked the files’ ease of use the best, and Dr. Jackfert said, “I also liked how smoothly the fi les went through the canals—no bumps or hiccups.” Dr. Paul Kaplan appreciated “the fact that there was a sequential order to follow so as to negotiate the canal without being too conservative or too aggressive,” and Dr. Olowoyo said, “I spent less time cleaning and shaping canals because I didn’t have to use a lot of fi les.”

He also suggested adding “options for very large canals,” while Dr. Jackfert thought the fi les could be color coded better.

Improved Treatment Outcomes

Dr. Nicosia shared, “I had an elderly patient where access was limited for several reasons. [Using ZenFlex CM fi les], I was able to quickly and efficiently navigate and shape the canal, which both the patient and I greatly appreciated.”

“I had a 2-canal lower second premolar and was able to get into both canals without being overly aggressive, and the gutta-percha went down easily into both canals,” Dr. Todd Sarubin recalled. “I even got a puff of cement out of the apex!”

Previously struggling with “difficult access to posterior teeth and MB canals that are dilacerated more than 60 degrees,” Dr. Chu shared that “the product was helpful when I had to negotiate a MB canal on tooth No. 2 more than 60 degrees.”

Similarly, Dr. Kaplan was treating a tooth No. 3 with very calcified canals when he discovered, “This fi le system allowed me to slowly and methodically make my way to all of the apices,” and more broadly, “it allowed me to negotiate even the most challenging canals with great results.”

Overall Satisfaction

“I am confident that this product will serve many endodontists well in their practices,” Dr. Kaplan said, and Dr. Henkel added, “It does everything a rotary [system] should do.”

“The ZenFlex CM rotary endodontic fi le system is a perfect adjunct to your everyday root canals, and for me, it worked great on the difficult cases as well,” Dr. Sarubin concluded. “It’s a great addition without any changes to my normal routine, and I couldn’t ask for a simpler system.”