by Michael S. Reddy, DMD, DMSc
A documentary film currently streaming on Netflix and other platforms would have viewers believe that endodontic therapy is the root of all evil (or at least a host of major diseases). Now, just as most people recognize the value of vaccinations, most also see the claims in this film as inaccurate. The scientific community certainly recognizes the anecdotal comments from those purported to be authorities as medical quackery.
Yet, judging from the reviews of “Root Cause,” there are some who — much like those who link vaccinations to autism — appear to have bought into the hype.
“Root Cause” follows an individual’s experiences after root canal treatment, including the alleged multiple systemic issues he claims are directly associated with the procedure.
(It’s worth noting here exactly what root canal treatment is. The procedure is prescribed when the pulp, the soft tissue containing blood vessels, nerves and connective tissue inside the root canal, becomes inflamed or infected. The condition can result from decay, repeated dental work, or trauma. An endodontist removes the inflamed or infected pulp — which is not essential for mature teeth — carefully cleans and shapes the inside of the root canal, then fills and seals the space. Afterward, the patient returns to his/her dentist, who will place a crown or other restoration on the tooth to protect and restore it to full function.)
The scientific premise of the film is based on research conducted almost 100 years ago that was later disproved. In the 1920s, a Canadian dentist, Dr. Weston Price, developed what was called “focal infection theory.” Focal infection theory asserted that many chronic diseases are caused by focal, or localized, infection. Adherence to this theory resulted in many extracted teeth and removal of tonsils in an effort to prevent all sorts of ailments. By the 1930s, health professionals began to reexamine the premise: Newer, carefully controlled research disproved the theory and called into question the results of previous studies. By the middle of the 20th century, the preventive removal of tonsils and wholesale extraction of teeth was coming to an end. Instead of extracting infected or fractured teeth, dentists have since preserved them with root canal therapy.
It bears repeating: Root canal therapy is the treatment for an infected (but live) tooth, not the cause of the infection. Root canal treatment — a common and safe procedure; some 25 million are performed each year — aims to eliminate bacteria from an infected tooth. This prevents reinfection and allows for preservation of the natural tooth. The patient then can continue to eat normally, and maintain one’s natural smile.
The film suggests the tooth with the removed nerve is dead, not unlike frostbitten or gangrenous flesh. Why you would leave a dead body part in the body? However, a tooth’s “dead” nerve simply does not respond to sensation — either owing to damage or a shot of Novocaine. This does not make it a zombie rotting corpse tooth; it still has a blood supply and attachment to the bone.
The movie makes other hysterical claims, such as: “Ninety-seven percent of patients with breast cancer had a root canal on the same side as the cancer.” Clearly this was meant to shock the audience and imply a cause and effect. Decades of research shows that there is no valid scientific link between endodontically-treated teeth and cancer. Correlation is not causation. I bet 97 percent of patients with a chronic condition also had water to drink in the last week.
Today we are bombarded with unvalidated information through both new and traditional channels. That overload is likely to get worse. Academic health centers, like UCSF, must continue to challenge health theories, and support fundamental scientific discovery and innovations in patient care. Vigilance is necessary, but so is taking a break now and then — perhaps even to catch a movie and view it for what is: entertainment.