Analyzing the First Root Canal Treatment on Film
Compiled by Rae Burach
This is the story behind a historic and significant piece of footage—believed to be the first-ever recording of a root canal treatment.
The footage was brought to AAE’s attention by Dr. Brad Gettleman after being passed along by Dr. Ben Johnson. We spoke with both about why the footage must continue to be shared and the insights it offers into the evolution of endodontic care. More than just a glimpse into the past, this footage invites reflection on how far the field has come and what we can still learn from these early moments captured on film.
Rae Burach: How did you acquire this historic footage?
Dr. Ben Johnson: I got it from Jacob Freedland, the 22nd Past President of the AAE (1964). He got it from Edwin C. Van Valey, the 25th Past President (1967), whose father practiced with M. L. Rhein in New York City. Freedland called me up and said, “I have this old film of a guy doing a root canal—could you restore it for us?” At the time it was the late 80s, early 90s. I got hold of a guy in California who was in the movie business. When I shipped it to him, he said, “Whoa, this is on nitrate film. This is from the early 1900s and could explode when we open the canister, so they charged me $10,000 just to open it! Then he called me back and said the film is actually in pretty good shape and he could convert it to video. At one point in time, I had it on a DVD playing in my office, so people in the waiting room would see it and go, “You’re not going to do it that way, are you?” No, no, no; that’s the way it was done 100 years ago.
Burach: What was your reaction when you first watched this footage? What stood out to you most about Dr. Rhein’s technique or equipment?
Dr. Johnson: Several things! He used the same contra-angle that I used in dental school. Of course, I went to school in the 1960s, but it’s pretty similar to the contra-angles we use today. The wide brush for cleaning off the burs—that was in the Union Broach catalog and may still be, for all I know! 1917 was before files were invented; k-files didn’t come out until 1919, so in 1917 they used apical picks. I found out that M. L. Rhein also developed an instrument that was a little bit oval—it was not circular because he knew canals were not circular—and that was innovative. He took two or three appointments to do those root canals he did in the film whereas now, most endos do things in one sitting or maybe two, but I was very impressed. It was cool to see that the principles of endodontics don’t change. Techniques do, but principles don’t. In part of that film, you see a woman putting some instruments into a cylinder-looking thing on a tray and starting a stopwatch. Our methods of sterilizing with autoclaves generally take 30-45 minutes. In the early 1900s, instruments were only sterilized for like 15-20 seconds. But I don’t discount what they were doing because that was a big time for bacteriology. And of course, this is decades before antibiotics, so you did what you could to avoid infection.
Dr. Brad Gettleman: The first thing that stood out to me about the video was that the “essentials for success” listed at the beginning are virtually the same as those we recognize today. Another early reaction I had was just how similar endodontic treatment remains compared to over 100 years ago. We’re still using many of the same foundational principles—such as isolation techniques, irrigating solutions, and obturation materials. It’s remarkable to consider that while a 12-month-old cell phone is practically obsolete, the core concepts of endodontic therapy have endured for more than a century. Of course, our instruments and materials have improved significantly, but the fundamental similarities are striking. What impressed me most about Dr. Rhein’s treatment was how remarkably effective it was, especially given the limited instrumentation available to him at the time. Also, the emphasis on disinfection was also quite evident—from the use of “bichloride solution” to the application of “ionization” to eliminate all “pathogenic focus.”
Burach: Given your experience in endodontics, what lessons have you drawn from this footage, or what can today’s and future clinicians draw from it?
Dr. Johnson: When I went through graduate school it was 1971 to 1973. We didn’t become a specialty until 1964, so we were still in our first decade. I had to read all the literature ever published about endodontics going back to the 1800s, so what’s in this video isn’t necessarily new to me, but it’s informative. In the late 1980s I videotaped some procedures because it’s so much more informative than just slides, but getting things organized to videotape and go seamlessly without too many cuts—that’s very difficult. I can only imagine how difficult it was for Rhein to do on film in 1917. I was very impressed. Rhein was just one of about a half dozen men who were well known at that point in history for doing endodontics. I’ve always given copies away to colleagues who ask or direct them to wherever it is online. I think it’s important for us to know where we came from. It gives you a perspective of where you are and an insight into where you’re going.
Dr. Gettleman: As an educator, I can use the video to introduce a lecture or seminar on the history of endodontics. It can be used to discuss the challenges faced by early practitioners, including limited instruments, rudimentary asepsis, and less scientific understanding. It highlights Dr. Rhein’s pioneering efforts and how early attempts laid the groundwork for modern techniques. I can assign students to compare Dr. Rhein’s techniques with current best practices and ask them to identify elements that have remained conceptually consistent versus those that have dramatically changed. We can focus on the focal infection theory, which was widely accepted in Rhein’s era and contributed to the extraction of many restorable teeth. This helps students see continuity in clinical thinking despite technological advances.
Burach: How does this footage add to our understanding of the evolution of root canal therapy?
Dr. Gettleman: Diagnosis and Imaging: Dr. Rhein relied solely on clinical signs and rudimentary radiographs to make a diagnosis. Endodontic diagnosis has advanced significantly since that time, with the advent of digital radiography, CBCT (cone beam computed tomography), electric pulp testing, and thermal testing, allowing for more precise localization and assessment of pulpal and periapical conditions.
Instrumentation: Dr. Rhein used hand files (not finger files)—which were unstandardized, difficult to use, and prone to breakage. Hand files have been replaced by finger files and instruments have become standardized. While instrumentation has evolved with nickel-titanium rotary and reciprocating files, which are more flexible, fracture-resistant, and efficient, improving both safety and effectiveness in shaping the canal system.
Irrigation and Disinfection: Irrigants and solutions were not nearly as efficacious as they are today. Additionally, practitioners had virtually no understanding of microbial biofilms. We now use sodium hypochlorite, EDTA, chlorhexidine, and advanced techniques such as ultrasonic activation, laser activated irrigation systems, as well as other irrigation systems to disrupt biofilms and achieve thorough disinfection.
Obturation: Obturating materials included gutta-percha, but techniques were inconsistent and often did not achieve a true seal. Sealer-cement was not used in the video! While gutta-percha remains the core material, obturation techniques have improved with thermoplasticized delivery, bioceramic sealers, and hydraulic condensation, leading to much more predictable results!
Restoration and Coronal Seal: Limited focus was placed on long-term coronal restoration, often resulting in reinfection. Emphasis on restorative endodontics has led to improved outcomes through immediate, bonded, well-sealed restorations that preserve tooth structure and prevent leakage.
Sterilization and Asepsis: Asepsis was rudimentary; sterile gloves and masks were not consistently used, and rubber dam usage was variable. However, Dr. Rhein did use a rubber dam in his video. Strict infection control protocols are standard.
Burach: In your view, what was Rhein’s most forward-thinking idea, given his time?
Dr. Gettleman: His emphasis on preserving the natural tooth through root canal therapy—at a time when extraction was the norm, particularly under the influence of the focal infection theory. He was foreshadowing the principles that now form the foundation of contemporary endodontics.
In the early 20th century, many physicians and dentists believed that infected teeth contributed to systemic illness, leading to widespread extractions—even of restorable teeth. Despite practicing in this era, Dr. Rhein promoted conservative treatment aimed at retaining the natural dentition, which aligns with modern endodontic philosophy. His use of aseptic technique, rubber dam isolation, and efforts to clean, shape, and fill the canal system showed a surprisingly modern understanding of disease control and tooth preservation.
Rae Burach is the AAE’s integrated communications specialist.