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Root canals can cause cancer? Don’t believe the viral hype.

PictureIs this going to kill you?

I am taking a break from the diet and exercise series that I have been working on to go back to a dental related topic that has been going around social media for a couple of years now.  How many of you had read this article, or articles similar to it?

http://humansarefree.com/2014/02/shocking-connection-97-of-all-terminal.html

This kind of “evidence” is being put out there and people believe it. But should they? Is there any truth to this? I am a skeptic of everything I read; I do not believe anything until I see proof, multiple times, from multiple sources. Until then, things are just plausible explanations and alternative hypotheses must be explored. Even things we thought true in the past can become false in the future. So let’s look at the evidence behind this article.

Let us talk about root canals and systemic disease. (sorry, this is gonna be a long one!)

First of all, take a look at the writing style in the article. It is written in a manner that is supposed to convince you. One part of being a researcher is finding evidence, but unfortunately, the more important part is trying to make other people believe what you find out is true. For me, it is the evidence that speaks for itself, but…people can be swayed by convincing writing. For example, halfway down the page in big bold print it says:

Westin A. Price: World’s Greatest Dentist

No way! I hope he got a coffee mug and a t-shirt for that award!

When an author does this, what they are trying to do is add credibility to what he/she is saying, because someone really awesome said it before, or did the research. Do not be blinded by tactics like this: look at the evidence.

The second part of the writing style that frustrates me is that the author is using deception. Unfortunately, the term root canal means two things. It describes the space within the root where the blood vessels, nerves and living cells of the dental pulp reside. It also, however, is a common term for the dental treatment where this component is cleaned up (the nerves and all the other stuff are removed) and the root canal system is then sealed. When someone says, “aw man the dentist says I need a root canal”, really what they should be saying is, “oh man the dentist said I need non-surgical endodontic therapy“…..but….who says that???

The term “root canal” therefore applies to both an anatomic structure, and is also a poorly chosen common term for an endodontic treatment because of the double meaning. Saying “root canal” is like saying “leg”; they are both anatomic terms. But say you break your leg and need a cast, you do not say I am going to need a “leg” you say I am going to need a “cast”. In the case of teeth, if the “root canal” gets infected, you commonly say you need a “root canal”…….confusing!!!!

So….the long winding point behind this is that in this article, the author uses this common confusion to his advantage.  He actually does an ok job of explaining the bacteria that can infect the root canal system (although he missed some key bacteria eg. e. faecalis), but he does not describe the “root canal” treatment (endodontic therapy). He tries to make connections between the infected roots and all of these systemic diseases, including cancer, and then utilizes a couple of references to show the correlation between endodontic therapy and cancer. Those are two different things, but he groups them together under the general term “root canal”….this is confusing and wrong. He is purposefully using this tactic to mislead people! He says that “root canals” are causing all of these awful things and that dentists are horrible for recommending them, but it is unclear whether he is talking about infected root canal systems, or non-surgical endodontic therapy. Shameful writing.

Ok enough about writing style…..what about the evidence? Let’s be nerds and actually ask the correct questions.


PictureFUNGI!

1. Can root canal systems get infected?

Well of course! The mouth is so nasty and filthy. It is teaming with MILLIONS of bacteria, viruses and fungi. If the seal of a tooth is broken via caries (cavities) or trauma, then these bacteria enter the root canal system. If the tooth can no longer can defend itself and the nerves, cells and blood vessels die, the bacteria win and there is a root canal infection. These bacteria live in the root and expel toxins out of the tip of the root to which body then mounts an immune response around the root.

This is when people show up at the dentist: they have a throbbing, painful mass of pus stuck within their jaws. Yum. Like the aforementioned article said, many of these bacteria are “anaerobic” which tend to be bad guys because they can live in low oxygen environments. This topic has been studied extensively, for both primary and recurrent root canal infections.
Article about the bacteria in the roots


PictureTransient Bacterium

2. Can this root canal infection travel to other parts of the body?If we are trying to prove that bacteria within the root can be causing a problem elsewhere, we have to prove that these bacteria can get out of the root system and enter the blood stream. The presence of bacteria in the blood is termed BACTEREMIA.

For people with root infections, one study found that even though people had a root canal infection….less than 10% of them had bacteremia; the bacteria are pretty confined to the root systems. After non-surgical endodontic treatment, however, 30% did develop a temporary increase in bacteria in their blood. This is not new information; we have known for a long time that dental procedures can cause bacteremia.
non-surgical endodontic therapy and bacteremia 

For those keeners out there, this is a pretty good review (expert opinion paper) on root canal infections:
Root infection article

3. Is transient bacteremia during (and after) dental procedures dangerous?
In other words, do infected root canal systems cause the problems that are stated in the Mercola article?

For most people, this bacteremia is not long term (transient), and is totally manageable by the immune system. But….there is a subset of people with a history of heart conditions, for which antibiotics are currently recommended for if they are undergoing dental treatment. In the past, the list of health conditions that antibiotics were given to patients for dental procedures was huge! But as researchers have been looking at the risk of antibiotic resistance in comparison to the risk of serious complications from bacteremia, this list of conditions has shrunk substantially to a very specific set. Check them out here:

AMERICAN HEART ASSOCIATION RECOMMENDATIONS
Orthopaedic Surgeons statement

Imagine you are a researcher and want to assess whether antibiotics are necessary for these “at risk” groups. What do you have to do? You have to find a bunch of people who are at risk, such as people with a history of infective endocarditis (an infection of the heart valves), and then split them up into two groups. One group gets dental work with antibiotics and the other group doesn’t. Infective endocarditis is serious stuff and can be fatal….are you going to sign up for the non-antibiotic group? NO! This kind of study is unethical.

So the only evidence we really have to draw from is from RESTROSPECTIVE studies, meaning we look back and see if someone who has had an incidence of endocarditis also has had dental work in the past. If you look at all of the studies, the evidence is really inconclusive….yet….we prescribe antibiotics because we want to make sure we cover all of the bases….(or something else).
Cochrane review on antibiotic prophylaxis and endocarditis

One of the problems with retrospective research is that we cannot definitively point out the cause. In the case of bacteremia from dental procedures causing systemic complications, we cannot rule out other sources of bacteremia as a cause.

Brushing your teeth, flossing, chewing gum and eating, can all cause bacteremia as well!!!! Yes, us dental nerds have researched this topic. Basically every time you do any of those things you experience a transient bacteremia: Bacteremia from Everyday Oral Activities (B-EOA). There is some evidence that the worse condition your gums are in, the greater the bacteremia during brushing (but not necessarily for flossing or chewing).
B-EOA cochrane database review

So are you going to stop brushing your teeth? Or take antibiotics every time you want to double double your refreshment? Probably not, that is ludicrous speed. You can see how there is a debate in health care whether antibiotic prophylaxis is necessary because people experience bacteremia all the time and are not dropping dead!

In fact, there is more and more evidence to the contrary. Transient bacteremias from dental procedures may not necessarily increase the risk of adverse events in at risk populations:
Dental procedures and heart attacks
Dental procedures and joint infections

Remember how Mercola mentioned that the greatest dentist in the world gave a bunny a heart attack by putting a human tooth under its skin? Well, humans who have had heart attacks, are not necessarily more prone to heart attacks if they have dental procedures done….the poor bunny may have died for nothing.


PictureDo you think this is a logical conclusion?

4. Is non-surgical endodontic therapy (“root canal” treatment) dangerous, or linked to diseases?Again, this is really hard to research. We would have to perform endodontics on people, and follow them to see if we cause, say, breast cancer (like in the Mercola article). The reality is that this evidence just does not exist. We know that there are a bunch of things that are correlated, but have not really proven that one things (eg. endodontic therapy) causes the other (eg. cancer).
A good review of endodontic therapy and systemic diseaseOn the other hand, you can easily look through the data of a retrospective study and find that a group of people with a specific disease share a specific trait. Mercola says that one article found that 93% of women with breast cancer had a non-surgical endodontic therapy (although he says “root canal”, how lay). Well I bet 100% of those women drank water, and most paid taxes. They probably fell in love at some point in their lives too. Do all of those things therefore cause cancer because they got cancer after doing them? UNLIKELY! I know that it is a facetious hyperbole, but it is true…these would just be correlations. He needs to prove causality….and that evidence just does not currently exist.Furthermore, there are plausible alternative hypotheses.

One of these possible alternative hypotheses is that people who are ill are more likely to require non-surgical endodontic therapy. For example, many people who have cancer will undergo chemotherapy or radiation therapy, or a combination of both. Both of these treatments are very difficult to go through and can have devastating effects on the mouth and salivary glands.

Over 75% (if not all) of patients undergoing chemotherapy experience painful mouth ulcers called mucositis. This condition makes it virtually impossible to perform oral hygiene or to eat regular healthy meals. If the salivary glands are affected, people get Xerostomia, a term for reduced salivary flow.  If radiation is involved near the head and neck, reductions in blood flow to the bone and teeth, and scarring of the muscles of the jaw can occur.

This combination of signs and symptoms is a recipe for disaster for the teeth; people undergoing cancer treatment often get rampant caries which leads to infected root canal systems. If teeth are at risk for gum or root infections, and there is time before the chemo or radiation therapy begins, they are often extracted. More often than not, however, people begin their treatment ASAP and there is not enough time to extract the teeth and let jaw bone heal. The last thing you want is someone starting their therapy with a huge hole in their jaws. In people with infected roots who are immune suppressed (like those undergoing treatments for Cancer), non-surgical endodontic therapy is often performed in lieu of extraction because of concerns with altered healing of the jaw bone and risk of post extraction infection.
Oral Complications and Management Strategies for Patients Undergoing Cancer Therapy

This is a much more plausible reason as to why people who have had cancer have also had “root canals”. And notice….it is not the cancer that is causing the need for endodontic therapy, but it is a combination of variables. There is no causation here…cancer does not cause the need for root canal therapy and vice versa.


PictureA root infection spewing pus into the mouth. Yum!

5. What are the alternatives to endodontic therapy?

Aside from endodontic therapy, when you have an infected root, there are really two choices. You can live with the infected tooth that is spewing toxins into your jawbone and causing an inflammatory reaction and live in pain because of the pressure, until the infection eats its way through your jawbone and gums and starts draining, thus relieving the pressure. If you are lucky, it drains into your mouth. MMMMM pus in your mouth. So gross, but I see it too often. If you are unlucky, it drains into somewhere dangerous, like the floor of your mouth or back of your throat and you get a life threatening swelling. Those two outcomes both suck.

The other option is: you take the tooth out. Yes that works. It gets rid of the nidus of infection, but then you are short one tooth, which, yea, is not going to kill you, but can decrease your quality of life and self confidence if it is smack in the middle of your face. How to replace this missing tooth is another story…or specialty degree really.

On an aside, the Mercola article talks about how “biological” dentists are trained to extract teeth in a safe and healthy way, unlike regular dentists. That is a load of fertilizer. People get bacteremia from chewing. How in the world is a someone supposed to take out a tooth without causing bacteremia as well? It is just ridiculous.

In fact….one article found that almost 100% of patients experienced a bacteremia after extraction of a tooth! That is more than double the rate for non-surgical endodontics! Well, I guess the extractions were not being done by biological dentists….haha.
Bacteremia after dental extractions

Well if you read along this far I am very impressed! I will be even more impressed if you actually clicked the links! As you can see, I have taken a much different approach than the Mercola article…..you can go and read all of the articles that I have referred to yourselves and make your own informed decisions. He quoted a bunch of “research” that is non-existent on pubmed or google scholar…..I have no idea how to find it! If this was really ground breaking research, it would be in some sort of popular database….but I guess it could be “publication bias”.

I am not asking you to believe me because I am a dental specialist; I am providing you articles with a high level of evidence for you to read and make your own decisions. And besides, my opinion sucks because the title of “world’s best dentist” is already taken. Who would believe anyone other than the great Dr. Price? He was a good Canadian kid.

I doubt that this blog will go viral like the other articles have, because, let’s face it, it was nerdy, factual and boring. Those well distributed articles have the wow factor of making a bold and scary statement, so they catch fire and make the rounds. But…. perhaps every time you see that article posted on your friend’s Facebook wall you can post this on it right back, so we can try to get people to look at the actual evidence and develop their own educated conclusions.

Don’t believe the hype! Check things out for yourselves!

Thanks for reading!
Dr. Dave
drdalfaro@drbridger.com

3/1/2014
#RootCanalCanCauseCancerHype

2 replies »

  1. Very good article it relieved a lot of fears about having a root canal done. I’m a cancer survivor that has had chemo & radiation and am always search and reading about this may have effected my amune (sp?) system. When I Googled “are root canals safe” I was a little freaked out. Your article help me sort it all out. Prepare to be impressed as I plan to read from a lot of your links. Thank you very much. Julia.
    ps. Loved your humor😀.

    Like

    • Yes, Julia.
      It’s very confusing with the many conflicting articles, videos which totally contradict each other. I find that there are many fake news, fake Celebrities’ opinion when they are not an authority.
      Watch my new YouTube on Science-based Medicine vs. Evidence-Based Medicine and be throughly shocked by the wide acceptance of pseudo-medicine like Acupuncture, many New Age healings.
      https://goo.gl/xqsMhz

      Like

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