Welcome to Running: A FEVER. My name is Michael Davis, and this is a show about fitness, diet, and medicine. My goal is to live a long, healthy, happy, active life right up to the very end. It’s all about livin’ long and lovin’ life.

Today’s topic is one a lot of people dread before they ever sit in the chair: the root canal. I’m going to tell you what it actually is, how the modern procedure works in plain English, why someone needs one, a little history, why the reputation got so scary, and what has changed in roughly the last thirty years. I’ll also talk about my own root canal, which I had last week.

A root canal (the treatment, not the anatomy) is endodontic therapy. Endodontics is the branch of dentistry that deals with the inside of the tooth.

Inside every tooth is a soft tissue called the pulp. The pulp is made up of nerves, blood vessels, and connective tissue. It sits in a chamber up in the crown of the tooth and runs down thin tunnels in the roots. Those tunnels are the root canals. When the pulp gets irreversibly inflamed or infected, that living tissue can die. Bacteria can travel out the tip of the root into the bone and create an abscess.

A root canal treatment removes that diseased pulp, cleans and shapes the canal system, disinfects it, and seals it. The only alternative is extraction. Saving a restorable natural tooth is usually preferable to pulling it: you keep your bite, your neighboring teeth stay put, and you avoid the cascade of replacement options.

People hear “root canal” and think you’re removing the roots. You’re not. The roots stay. You’re cleaning the canals inside them.

How does it work?

Diagnosis first. Your dentist or an endodontist (a specialist in this work) looks at symptoms, tests the tooth, and takes images. That might be ordinary dental X-rays; in trickier cases it can include cone-beam CT, which gives a three-dimensional look at the roots and surrounding bone.

Then anesthesia. Local anesthetic numbs the tooth and the soft tissue around it. Modern local anesthetics and supplemental techniques are a big reason the old horror stories don’t match most modern visits. The American Association of Endodontists’ patient messaging is blunt on this point: with today’s anesthetics, the discomfort of a root canal is often similar to getting a filling, once you’re numb. In my case, I was completely numb, and there was no pain whatsoever during the procedure, just a little pressure and vibration.

Isolation. A thin sheet called a rubber dam goes around the tooth so saliva stays out and the field stays clean and dry. That is infection control, not theater. The cool thing about this is that you don’t have a bunch of stuff trying to go down your throat. It all stays above the rubber sheet, where they suction it off.

Access. The dentist makes a small opening through the chewing surface or the back of the tooth into the pulp chamber. In my case, he had to go straight down through the top because I had a crown on that tooth. I also had a root canal 10 years ago in one of my front teeth. In that case, they went in through the back of the tooth.

Clean and shape. Tiny instruments remove the pulp and shape the canals so irrigants can reach the full length. Older practice leaned heavily on hand files. Modern practice often uses flexible nickel-titanium rotary or reciprocating files that follow curved canals more predictably.

Irrigate. Chemical irrigants, commonly sodium hypochlorite among others, flush out bacteria, debris, and leftover tissue. Activation methods can help those irrigants work deeper into the canal system. Shaping alone does not clean everything; chemistry matters.

Fill. Once the canals are cleaned and dried, they’re filled, most classically with a rubber-like material called gutta-percha plus a sealer. Newer bioceramic sealers are part of the modern toolkit. The idea is a dense, biocompatible seal so bacteria don’t have an open highway back in.

Then a temporary filling goes on top. Because a tooth that needed a root canal is often structurally weakened by deep decay, a crack, or a big old filling, a permanent crown is frequently the final protection, especially on back teeth that take heavy bite force. Timing and materials are between you and your dentist. I already had a crown on this tooth, and the endodontist was skilled enough not to damage it during the procedure, so I didn’t have to get another crown.

One visit or two is common. Complex anatomy, severe infection, or a tough retreatment can take longer. Your clinician’s plan wins over any podcast timeline.

Today I went to my regular dentist to get a permanent filling to replace the temporary one the endodontist put in. No numbing was required, and it was a quick, easy, inexpensive visit. The reason for this two-step process is specialization in the modern dental world. An endodontist is a specialist in what he does. Your regular dentist is a specialist in tooth restoration.

Why would you need a root canal?

The usual culprits:

• Deep decay that reaches the pulp
• A crack or fracture that opens a path for bacteria
• Trauma, a blow to the mouth that damages the pulp even if the tooth looks okay on the outside
• A failing restoration that lets bacteria under the seal
• An abscess that has already formed at the root tip

The pain people associate with “needing a root canal” is usually the infection and inflammation talking: pressure, throbbing, lingering sensitivity to hot or cold, pain on biting, and swelling. The modern procedure itself, when you’re properly numb, is not supposed to be the torture chamber of pop culture. Untreated infection is the problem you don’t want to sit on. A tooth abscess does not reliably “go away” on its own; if it drains, the pain can drop and fool you into thinking you’re fine while the infection is still there. The infection is the real source of the pain. My endodontist started me on antibiotics several days before the procedure, and the pain went away before we even got to it. Before that, my regular dentist had prescribed hydrocodone, which completely took the pain away so I could get by until my first visit with the endodontist.

But antibiotics alone don’t clean the inside of a tooth, so you still need to see your dentist and get it taken care of.

Here’s some history I think is interesting.

People have been poking at infected teeth for a very long time. Archaeological finds include ancient attempts at drainage and even a bronze wire in a tooth from roughly the second or third century BC, interpreted by some researchers as an early effort to treat an infected pulp. For centuries, the practical options were crude drainage or extraction. Pain relief often meant pulling the tooth.

In the early modern European tradition, figures like Pierre Fauchard in the 1700s pushed dentistry toward a more systematic craft. That was still a world away from what we do now, but it was a step out of pure folk practice.

In the 1800s, instruments improved. Edwin Maynard is often credited with adapting watch-spring tools into early root canal instruments. Around the middle of the century, gutta-percha, the same rubber-like material still used in evolved form today, entered endodontic filling practice.

Then germ theory changed the mental model. Willoughby D. Miller and others in the late nineteenth century connected oral bacteria to disease inside the tooth and beyond, replacing the old “tooth worm” stories. X-rays in the early twentieth century let dentists see what they were treating. Effective local anesthesia made the work humane.

Endodontics organized as a community in the 1940s. The American Association of Endodontists traces its founding to 1943, and the American Dental Association later recognized endodontics as a specialty. The twentieth century turned “try to save the tooth scientifically” into a real discipline.

If you grew up after 1976, you may not need me to explain why “root canal” sounds like a threat. Marathon Man, the film with Dustin Hoffman and Laurence Olivier, burned dental torture into popular culture with the line “Is it safe?” It wasn’t a documentary about endodontics. It was a thriller using dentistry as horror. But cultural scars stick. Pair that with our grandparents’ memories of dentistry before reliable anesthesia, high-speed drills, and modern infection control, and you get a reputation that outruns the current procedure.

There’s a second reputation problem, and it’s pseudoscience with a long half-life.

In the 1920s, dentist Weston A. Price pushed a version of the “focal infection” idea: that teeth treated with root canals harbored bacteria and toxins that caused systemic diseases such as arthritis, heart disease, you name it. His studies were poorly controlled by modern standards. Better work in the following decades did not support his claims. A mid-century review in the Journal of the American Dental Association famously criticized that research for lacking proper controls and for using extreme bacterial doses that don’t map to real patients. The damage was still real: an era of needless extractions sold as prevention.

Those myths keep getting rebooted. The documentary Root Cause recycled the panic for a streaming audience, presenting root canals as a hidden cause of serious illness, plus meridian-line claims that are not how anatomy works. Dental organizations pushed back hard, and the film was pulled from Netflix in 2019 amid that criticism. McGill University’s Office for Science and Society has a clear, readable defense of root canal treatment that walks through Price, the documentary, and why extraction on principle is not evidence-based care.

The American Association of Endodontists’ patient myth pages say the quiet part out loud: there is no valid scientific evidence linking root canal treatment to cancer or to systemic disease elsewhere in the body. Modern endodontic care removes the infected tissue; it does not plant a time bomb.

Remember that oral health and overall health are connected. Gum disease and chronic oral infection are not trivial. That is not the same claim as “a properly treated root canal will give you cancer.” Don’t let a scary documentary talk you into pulling a savable tooth without a real clinical reason. And don’t take a podcast as your treatment plan. Talk to a dentist or endodontist you trust.

What’s changed in the last 30 years?

This is the part the Marathon Man generation never got:

• Better local anesthetics and supplemental anesthesia techniques for when a hot, infected tooth is harder to numb
• Nickel-titanium rotary and reciprocating files that flex through curves instead of fighting them with stiff stainless steel the whole way
• Routine rubber-dam isolation as the standard of care
• Digital radiography and, when needed, CBCT for three-dimensional diagnosis
• Operating microscopes, with magnification and light so the clinician can actually see fine anatomy, missed canals, and cracks
• Improved irrigants and activation so disinfection isn’t just “file and hope”
• Bioceramic sealers and better obturation materials and techniques
• Often shorter, more predictable visits than the multi-appointment marathons of earlier eras

My endodontist and his assistant took X-rays during the procedure to track their progress.

The AAE’s public line is worth repeating: for most patients who are adequately numb, a root canal today should feel like it’s in the same ballpark as a routine filling. Tenderness for a few days afterward can happen as the tissues calm down, but that’s different from the procedure itself being medieval.

None of this means every case is easy. Anatomy varies. Retreatment of an old, failing root canal is its own challenge. Some teeth can’t be saved. But the average experience in 2020s endodontics is not your grandfather’s drill-and-suffer story.

If you’re staring down a root canal recommendation, get the facts from your clinician, not from a thriller or a streaming scare piece. Ask about the diagnosis, whether the tooth is restorable, what the restoration plan is after the canals are filled, and what recovery should look like for you. Saving a tooth when you can is often the path that keeps you chewing, training, and living without a hole in your smile, which fits the whole point of this show: livin’ long and lovin’ life.

Until next time, if you’ve got the fever, keep it burning, and if you don’t, catch the fever, and I will talk to you next time on Running: A FEVER.

References:
AAE: Root canal treatment (patient hub): https://www.aae.org/patients/root-canal-treatment/
AAE: What is a root canal?: https://www.aae.org/patients/root-canal-treatment/what-is-a-root-canal/
AAE: Myths about root canals: https://www.aae.org/patients/root-canal-treatment/myths-root-canals/
AAE: Root canal safety: https://www.aae.org/specialty/clinical-resources/root-canal-safety/
AAE: Endodontic history: https://www.aae.org/specialty/endodontic-history/
AAE: Specialty and association histories: https://www.aae.org/specialty/about-aae/aae-history/specialty-association-histories/
Mayo Clinic: Root canal treatment: https://www.mayoclinic.org/diseases-conditions/tooth-abscess/in-depth/root-canal/art-20585454
Mayo Clinic: Tooth abscess (symptoms and causes): https://www.mayoclinic.org/diseases-conditions/tooth-abscess/symptoms-causes/syc-20350901
Mayo Clinic: Tooth abscess (diagnosis and treatment): https://www.mayoclinic.org/diseases-conditions/tooth-abscess/diagnosis-treatment/drc-20350907
McGill Office for Science and Society: In Defence of the Maligned Root Canal: https://www.mcgill.ca/oss/article/health-and-nutrition/defence-maligned-root-canal
Marathon Man (film), Wikipedia: https://en.wikipedia.org/wiki/Marathon_Man_(film)
PMC: Modern Endodontics: https://pmc.ncbi.nlm.nih.gov/articles/PMC9857497/
PMC: Historical and Contemporary Perspectives on the Microbiological Aspects of Endodontics: https://pmc.ncbi.nlm.nih.gov/articles/PMC6313668/

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