1001 Uses For Dental Floss #63- Mouth Bacteria Linked to Colon Cancer

image from United States Department of Health and Human Services,

Fusobacterium nucleatum, a bacterium found in the mouth, and specifically in dental plaque, has been shown to also be accelerate the growth of cancer cells in the colon and rectum (your lower gut), where they are also found.

In the mouth, dental plaque is found on the surfaces of the teeth if they aren’t kept properly clean by brushing and flossing. It is a sticky mass of various kinds of bacteria and their chemical products, some of which are damaging to the teeth or to the gums. This is why it’s important to keep your teeth clean by flossing and brushing every day. some of which allow the plaque to be sticky and keep the bacteria next to the teeth instead of washing away as saliva flows past them. 

Please be warned that some strange-sounding chemical names will be mentioned here, but this isn’t me trying to scare you off reading the real message of this story. Just keep going. It’s actually pretty simple to understand.

A recent scientific research paper ((http://embor.embopress.org/content/early/2019/03/01/embr.201847638) has shown that these specific bacteria, produce a substance (FadA adhesin), involved in sticking bacteria together in dental plaque in the mouth, also accelerates the growth of colorectal cancer cells. The colorectal cancer cells themselves produce their own substance, (Annexin A1) which isn’t made by normal (non-cancerous) cells. That material allows the cancer cells to communicate with other cancer cells and make them divide and grow faster and to be more aggressive.

What the FadA adhesin does is help the cancer cells’ Annexin A1 to work better, but not only that, it also helps the attachment of more bacteria and in this way produce more of their substance, which stimulates the cancer cells to make more of their own product, on and on, and so on, so that the end result is that the cancer grows better and faster. This action is known as a positive feedback loop. The next step would be to find medications which may prevent this interaction, interfering with the way the cancer grows. 

It’s important to understand that cancer is a very complex disease or, really, group of diseases, and there are many steps along the way before it will, and hopefully in the not too distant future, be controlled or maybe even cured, so this is only one small step along that long, twisting path. Cancer research is making great strides forward, and will continue to do that because of the dedicated minds of the scientists involved in that research.

It’s also important to know that oral hygiene, brushing and flossing, can’t be expected to affect this cancer disease process, but do it for all the other good reasons. This type of bacteria, as I said, is common in the mouth and the mouth can’t be made sterile. That would cause other problems, because some bacteria are actually useful to our health–they’re our friends.

As I continue to say, though, remember to brush and also to floss. Make it a habit that you do very day. You’ll be healthier, and therefore happier, if you do.


1001 Uses For Dental Floss # 62- A Woman Scribe Got The Blues


A Woman Scribe Got The Blues

You may recall the name–Dr. Christina Warinner, who is an anthropologist, last mentioned in these pages (1001 Uses #4) because she discovered that ancient humans used one type of grass to floss their teeth. Well, here she is again, this time with colleague Anna Radini of the University of York in England, still studying dental calculus, AKA tartar, but on the teeth of a medieval woman’s skeleton. 

What is special about this woman and this skeleton, and these teeth? Well, this anonymous woman’s remains were disinterred from the graveyard of a monastery of a small religious community at Dalheim, Germany. And what they did at this monastery was create illuminated manuscripts. 

Monastery–monks, right? Wrong, sort of. It turns out that this woman was somehow involved with creating these illuminated manuscripts. You know the ones, those beautifully illustrated hand-written biblical texts displaying fanciful brightly multicoloured drawings of saints and demons and dragons along their margins and decorated with real gold foil. 

That’s not done anymore, not since Johannes Gutenberg put an end to all that when he invented the printing press and inaugurated the Age of the Book (I made that title up, but he did do that.) Anyway, I digress. Back to the blue dye.

Anyway, what does that have to do with anything? It turns out that this woman’s teeth had tartar (there were no dental hygienists around in those years to scrape it off–that’s why they called them the Dark Ages- no, not really) on them. And no one flossed, as far as I know. 

These researchers found that the tartar had a striking blue coloration which turned out to be lapis lazuli, a mineral which was ground to a powder and used in these illuminations.

Well, okay, so what? Well, not only that, but the coloration was unevenly distributed on her teeth, so it’s not like she was inhaling the powder while grinding it or from kissing the Bible at the monastery. There was more of the blue tint on her front teeth than in the back, and this suggests that she was probably using a brush, and licked it to make a fine point of the bristles, and in the process picked up some of the lapis lazuli on her teeth.And this means that she was one of the artists creating these illustrations. 

The only question I have is, why weren’t there any other dyes on her teeth, since other coloured minerals were also used? I don’t have the answer to that question, except maybe this woman specialized in applying this particular colour (like in an assembly line, an innovation supposedly invented by Henry Ford in the early 1900s.) 

Maybe further testing will find other dyes on other skeleton’s teeth in that cemetery. We’ll just have to wait with bated breath for the answer to this question.

In the meantime, floss regularly. And visit your dental hygienist at least twice a year. You don’t want some future archeologist checking out your teeth one day in the far future. I’m sure you have secrets you’d rather no one knew anything about.

1001 Uses For Dental Floss #61- Fluoride Toothpaste and Young Children

We’re back after a hiatus of a couple of years. Us smiling up at the top? No, that’s a mild form of dental fluorosis.


A recent report from the Centre for Disease Control and Prevention on the use of toothpaste and tooth-brushing patterns among children and adolescents (https://www.cdc.gov/mmwr/volumes/68/wr/mm6804a3.htm)suggests that young children are using and swallowing too much fluoridated toothpaste when brushing their teeth. They recommend that children under the age of 2 should use a non-fluoride toothpaste and those aged 3-6 should only use a pea-sized portion on their brushes.

Let’s dissect this advice down into its parts, or as they say these days, let’s unpack it. The prime idea here should be to do what is necessary, what is practical, and to not make compliance so difficult or complicated that it would turn some of us off from doing the right thing.

First of all, brushing is important. It should be done as soon as the teeth come into the mouth (about 6 months of age and later), preferably after each time a child eats (or drinks from the mom’s breast or a bottle), but since this is maybe impractical in some cases, like the middle of the night where mom is exhausted, do it at least once or twice a day. (Do it in the middle of the night too, if you can.) That way, bacteria won’t build up a layer thick enough to start retaining acid (from sugar breakdown by these germs) which will start to leach calcium from the tooth surface (and so cause tooth decay.)

Second, fluoride at proper levels has been shown over many years to be beneficial to tooth health, by changing the crystal structure of enamel so that the enamel is more resistant to acid. Fluoride has therefore been added to the water supply of many cities as a public health measure. Almost 200 million people in the U.S. and 300 million world-wide have fluoride added to their water supply.

Third, fluoride can enter tooth enamel in 2 ways, either when the teeth are still under the gums, and after they are already visible in the mouth. Before teeth come into the mouth, the enamel may still be forming and fluoride present in the bloodstream bathing these teeth increases the fluoride content as enamel is laid down as the outside layer of the teeth. After the teeth are already in the mouth, fluoride applied to the teeth strengthens the outer layer of enamel. Fluoride that moves from the blood into the saliva in the salivary glands also can contribute to this beneficial process.

Fourth, too much fluoride can cause white spots (see photo above) or lines on developing teeth (termed “fluorosis”), which are teeth which haven’t yet broken through the gums and entered the mouth. By the way, this growth of teeth from below the gums into the mouth is called “eruption”, sort of like a volcano erupts lava from underground onto the earth’s surface. I know, it’s a weird comparison but the term has been around for a long time, so what can you do?

If the concentration of fluoride your child is exposed to is significantly higher than 1.2 parts per million (ppm), fluorosis can result. If it is higher than that (the upper limit here is not well-defined), the enamel can be disrupted enough that surface defects, staining, and weakening of the enamel’s strength can happen. It’s therefore important that the fluoride concentration stays in the “Mama bear” zone (thanks, Goldilocks, for giving us this concept of just-rightness.) The two permanent upper front teeth, which are the most esthetically important teeth when we smile, have generally completed enamel formation between 15 to 24 months for boys, and between 21 and 30 months for girls, so fluorosis can happen to these teeth during this period.  Also, because we drink more when it’s hot, people living in a hot climate should probably have less fluoride added to their water, since they’ll drink more and absorb more fluoride, possibly producing fluorosis more easily.

Fifth, it’s clear that young children, if unsupervised, will not follow dental association guidelines (or listen to you, either.) Toothpaste, especially the fruit-flavoured children’s toothpastes, appeals to kids’ natural affinity for sweet flavours, so watch out.

Sixth, below the age of 6, children haven’t developed enough control over the swallowing reflex and the ability to spit to prevent swallowing of toothpaste. Some, if not most, will be swallowed. So, obviously, preparing the toothbrush with the right amount of fluoride toothpaste by a parent or supervising adult is very important. As for the right amount to put on the toothbrush, a very thin smear of toothpaste for kids below the age of 3, and a pea-sized blob, not more, is recommended after 3. The parent actively doing the brushing is really the best way to go.

So, finally, use of a non-fluoride toothpaste below the age of 3 is probably a good idea, and using a children’s fluoridated toothpaste, which has half the adult concentration of fluoride, from 3 to 6 years of age, is also recommended. And a parent should always be watching and helping young children brush their teeth. I hope all this is clear and convincing.

And don’t forget the dental floss (again, done by the parent), especially once the teeth next to each other are touching.

1001 Uses For Dental Floss #60- Neanderthal Kisses and Dental Plaque

Helene Rougier, anthropologist at California State University Northridge, in the United States, displays some of the 96 bones and three teeth from five Neanderthal individuals which were found in the Belgium Goyet cave. Credit: Emmanuel Dunand Getty Images

Neanderthals were amazing creatures. Much like us, and much not like us at all. And yet, archeologists have recently looked at hardened plaque, which is the same, I think, as what we know as calculus or tartar, the stuff your hygienist spends an hour scraping and vibrating off your teeth at your six-month visit to your dentist. The results are (for me, anyway) amazing.

The Neanderthals of El Sidrón Cave in northern Spain had a pretty hard time. Food was hard to come by, and they had to fight off predators, disease, and long, hard winters. By looking at the stuff stuck between their teeth in five fossil skulls, (some 50,000 years ago or more), it’s been found that they ate mushrooms, moss and pine nuts.

One individual may even have used plants and moulds to treat his diseases. Paleolithic medicine!

Laura Weyrich, a palaeomicrobiologist at the University of Adelaide in Australia co-led the study, and suggests that these findings “really paint a different picture, almost of their personalities, of really who they were.”

Christina Warinner, an archaeological geneticist at the Max Planck Institute for the Science of Human History in Jena, Germany, praises the team’s microbiome reconstructions. The mouths of Neanderthals seem to have been colonized by microbes rare in humans today.

Recent improvements in ancient DNA analysis, have allowed these trace sequences to be identified and have led to a bonanza of research into ancient plaque.

In a 2013 study, a team led by Alan Cooper at the University of Adelaide sequenced preserved plaque to show that major shifts in diet such as the large increase in starch because of settled farming some 10,000 years ago made for large changes in the human oral microbiome.

Weyrich’s team compared plaque DNA from Neanderthals from El Sidrón and from the Spy cave in Belgium. The analysis revealed that whereas Spy denizens seemed to consume woolly rhinoceros and wild sheep, El Sidrón’s foraged for plants, although . Hervé Bocherens, a palaeobiologist at the University of Tübingen, Germany, believes that thee two groups ate meat. Both ate mushrooms.

Amazingly, the El Sidrón Neanderthals probably also used plants to self-medicate. DNA from poplar trees (parts of which contain salicyclic acid, historically used in aspirin), and Penicillium mould (the source of penicillin) turned up on one individual’s teeth. Weyrich suspects that they were trying to treat a visible tooth abscess and a stomach infection caused by the bacterium Enterocytozoon bieneusi. Maybe eating mouldy grain could have caused this too, but the idea that these creatures, long thought to be primitive hulking brutes, as self-medicating and familiar with pharmacological approaches to disease is fascinating.

A microbe called Methanobrevibacter oralis is found in the mouths of modern humans, but genetic analysis shows that it was there in ancient humans at the same time as in the mouths of Neanderthals. This suggests the archaebacterium was transmitted between them. Were they kissing, or simply sharing food? Whatever they were doing together, they were together, turning on its head ideas that they were separate and always fighting for dominance.

“If you’re swapping spit between species, there’s kissing going on, or at least food sharing,” says Weyrich, “which would suggest that these interactions were much friendlier and much more intimate than anybody ever possibly imagined.”
So many amazing advances in our study of these ancient beings, who were largely misunderstood in the past, really changes our ideas of whre we came from and how alike we are to what came before us.

The original article in Scientific American by Ewen Callaway can be found at https://www.scientificamerican.com/article/neandertal-tooth-plaque-hints-at-meals-mdash-and-kisses/.

1001 Uses For Dental Floss #59- Fashion Toothpastes

A little late for the end-of-year holidays, but I can’t always be up-to-date on everything dental. Now toothpaste has joined so many other products as worthy of a fashion article. In Vogue Magazine, an article of 8 toothpaste products deemed worthy of being considered as gifts (and why not throw in some floss) was in the December 20 issue, just in time for those last-minute head-scratchers trying to come up with the ultimate unusual and impressive article for the gift stocking. They come in a variety of flavours, including:

1. David’s Natural Toothpaste, touted as being fluoride-free (actually not a good thing, in my professional opinion) and sulphate-free (I don’t know what the value of this is, but I’m not a chemist or public health person.

2. Lebon Cinnamon-Mint flavour

3. Jarvis Jasmine Mint

4. Theodent Kids, which has a chocolate flavour

5. Couto Pasta Dentifrica

6. Acca Cappa

7. Boka Mint Natural Toothpaste

They all look fancy and flavourful, and may make you feel good about taking care of your teeth, so check them out. Not an endorsement, though, just thought this was interesting. I haven’t looked into the prices or availability, though.

So, brush your teeth every day and floss them too. Again, floss your teeth.
But like one of my dentistry teachers once told his patients, only floss the teeth you want to keep. I case you have favourites.

To see the original Vogue article, go to:


1001 Uses For Dental Floss #56- Is Flossing Really Useless?

Globe and Mail columnist Margaret Wente recently wrote an article following up on the Associated Press’s dismissal of flossing as a useful adjunct to oral health, expressing, I guess, relief that finally she could ignore the advice she receives every time she goes to her dentist’s office. She seems to hate doing the flossing, and resents having an “expert” tell her what to do. Her article in the Globe and Mail, declaring the absolute uselessness of dental floss is, however, wrong on her part. What she says is a misreading of a misreading. The original article by the Associated Press claimed that flossing is useless, as evidenced by a lack of good scientific data supporting the practice, which simply means that a large enough double-blind study hasn’t been done, which I and the American Dental Association acknowledge. This is, however, mainly because the corporations who manufacture floss and toothbrushes and toothpaste and mouth rinse haven’t found it sufficiently important to finance such a study (no one else will because it’s not a matter of public health being threatened enough, like AIDS or Zika virus or Ebola do, which really, and rightly, scare people. Dental decay and gum disease, although very prevalent (dental caries affects more people in the world than any other infection), it doesn’t kill anyone (or hardly anyone, because it can, but rarely in the West), and their effects are slow and limited, for the most part, to the teeth, not the rest of the body. So who cares, right?

Luckily, there are journalists who are more thoughtful. Global News reporter Andrew Russell gives a much more balanced and nuanced picture of this subject.

It’s a little scary to see this issue turned into a controversy by people who dislike doing it, and so feel gratified, if not liberated, by what seems to be a reason for them to stop flossing. It’s more distressing, though, when those who shape public opinion in the news media misreport and misrepresent issues, and then pass them along to other reporters who, in a grotesque sort of broken telephone, blather on about issues which are then presented in a simplistic and distorted fashion to an audience who are unfamiliar with them and accept that whoever is doing the writing must be an “expert” on it. So the “experts” are deciding who the “experts” are, without really vetting the value of the information or disinformation they’re passing on. This doesn’t just apply to this small issue of flossing, but also to more important subjects which make the headlines of our newspapers and the ticker tape display on our news channels. Distressing.

Please continue to floss. It really is good for you.


1001 Uses For Dental Floss #55- The Story of Gulliver’s Floss

So, it seems that the Associated Press did a deep review of scientific papers studying flossing and found that, amazingly, FLOSSING IS USELESS! Sure, and Dewey won the presidency against Truman in the 1948 U.S. Presidential Election- they got that one right too. No one could be more surprised than me at this revelation, but sceptic that I am, I don’t believe it. In my heart (and experience) I know that flossing prevents both decay between teeth and gum disease, and I plan to go through all the articles cited investigating this. Give me a couple of months, though. There’s a lot to read.

While you’re waiting, though, here is another tall tale inspired by a comment by Chuck H., a Facebook friend of mine.

Many years ago, a man named Lemuel Gulliver travelled from one place to another, meeting all sorts of strange creatures. The best-known of these were the Liliputians, who appeared to be fully-formed humans, except they were very, very small. How small were they? Very, very small. Very, very, very, small. Minute. When Gulliver landed on Lilliput after a gale sank his ship, taking everyone but him to the bottom of the sea, he was exhausted from swimming, fighting the currents, and outpacing the sharks and other sea creatures bent on eating him. He fell asleep on the shore, and when he woke up later, he found himself surrounded by a horde of the tiny inhabitants of the island, who, being cautious about the possible danger from such a huge creature, had lashed him with rope, so that he couldn’t move a finger.

Gulliver, though, was, among many other things, a surgeon and dentist, and he mistook the ropes, which were pretty thin and fashioned from silk, for dental floss. Not having much else to do, Gulliver began to speak, describing his work and the terrible scourges he fought every day, dental decay and gum disease. Not being someone who surfed the net, which was not to be invented for several more centuries, he hadn’t read the Associated Press article on the futility of flossing, so he proceeded to preach on the value of the practice. Gulliver was such a good orator that the creatures of the island were soon convinced. By night, a few would sneak close to him and cut off a length or two of the silk lines and floss their teeth, and amazingly, within a few days they felt better, and had much better breath. This so impressed their friends that the practice spread across the island, and very soon, all of Lilliput had great oral hygiene. Because they used up the silk binding Gulliver, he was quickly able to free himself and soon took short walks across Lilliput. The tiny people of the island hailed Gulliver and wanted to make him their king. But Gulliver was a modest man. He didn’t want power. He just wanted to go forth to other lands, extolling the virtues of good oral hygiene habits far and wide. And this is why Jonathan Swift’s book about him is called Gulliver’s Travels, and not Gulliver’s Floss.

If you liked this story, go read the real Guliiver’s Travels, a satirical novel published in 1726 by Irishman Jonathan Swift, now available free online. It’s in the public domain. And continue to floss. It really does help. I’ve seen it happening.

1001 Uses For Dental Floss #54- Can Good Oral Hygiene Damage Your Body? Really?

Probably not.
Years ago, when I was a beginner dentist, I didn’t know much, but then a lot of others were in the same boat. At one time, the teeth were considered a focus of infection, a place which harboured bacteria just waiting to set forth and infect the rest of the body. Boy, did dentists feel maligned, something like weathermen who were blamed for every storm and cold font, tornado, and drought, just for being around.
There was then an orthodoxy surrounding dental treatment for patients who had various sorts of heart defects, such as damaged or defective heart valves, a history of heart valve replacement, a history of rheumatic fever, or other heart-related problems. All such individuals were given penicillin (or, if they were allergic to that, another antibiotic) for two days before treatment and then for a day after the procedure, because it was felt that bacteria such as Streptococcus mutans or Streptococcus viridans lodged in the gums and around teeth would get pushed into the blood and then travel to and colonize these damaged, sensitive surfaces of the heart. A few years later, the regimen (developed by the American Heart Foundation) got simpler and involved just a single dose of penicillin (or other as above) an hour before the dental treatment started.
More recently, realizing that people with these problems could seed their hearts with bacteria just by brushing (and flossing), it became clear that it was a fool’s errand to try to prevent these effects except where there were powerful reasons to try to do so: recent heart valve surgery (within the last year) or certain serious and complex developmental defects involving the heart, or a heart transplant. Unfortunately, it was not a good idea to have these patients on a continuous dose of antibiotics either. The free and easy way in which antibiotics were being used was becoming a danger in itself, because strains of antibiotic-resistant bacteria were arising due to their overuse.
So, at the time, there was also a concern that certain artificial implants, such as latex tubes placed to drain excess fluid from the brain, or artificial hip joints, might offer internal surfaces that could be colonized by mouth bacteria, and antibiotics might be useful against this possibility too. And then antibiotics for these cases fell out of fashion, too.
That was then. Here, now, we’re up against the same situation again. Recently, a woman with an artificial knee joint arrived in hospital with a painful infection in that site. Puzzled doctors opened up the knee and discovered that the infection was by another type of bacteria, this time Streptococcus gordonii, commonly found in the mouth, and decided that because the woman had recently started vigorous flossing, that must have pushed them into the blood, and the infection of the knee followed.

Of course it did. Obviously.

Same old story, blaming the teeth again.To which I say, maybe. And if history is any sort of guide any more, probably not.

Keep flossing.

1001 Uses For Dental Floss #53- A Squirrel with a Sweet Tooth

Another baby tooth-pulling story, as reported on CBC News (it wasn’t even a slow news day- the Brexit surprise just happened): A Montreal dad is in it for the big time. After entering the fray with the use of a drone to pull his daughter’s tooth last summer, 6-year-old Mila Freiheit’s father thought that the next step up would be to use a live animal to do the job. Luckily, not anything large and dangerous like a pitbull or a racehorse, just a squirrel with a sweet tooth. This girl’s dad attached the tooth via a length of floss to a granola bar. The squirrel gave a tug and off went the tooth, so loose that the floss just popped it out. He filmed it all with 3 cameras. And the squirrel didn’t have rabies.

What next? Mila still has a bunch of baby teeth that will be loosening up over the next 5 or 6 years, so this could really escalate. The ultimate, I think, would be to lure aliens to use their UFO to do the job. Failing that, (I don’t believe in aliens- sorry, Mulder and Scully) maybe a police car racing off to fight crime, or an elevator, with the little girl in it and the floss hanging out and attached to some object outside it, like a potted plant). How about using a float at the gay parade? Or maybe the dad can attach the tooth to Scotland as it tears itself away from England one of these days.

I have news for the dad, though. It’s illegal to feed squirrels in a park in Westmount. There’s a $50 fine for doing that. Will Mr. Freiheit be charged? Stay tuned. I hope the drone flight last year was legal.

Flossing is still legal though. Squirrels do it, sort of. So you keep doing it too.



1001 Uses For Dental Floss # 52- Greek Myths


The Myth of Theseus and the Minotaur (and Dental Floss)

You may have heard of the Minotaur, a half-man, half bull creature kept in the Labyrinth by Minos, the King of Crete. According to Greek myth, the Labyrinth was an artificial cave with winding, intersecting tunnels and blind ends so that no one who went in could ever unravel its secret pathways and escape, built by the engineer Daedalus (whose son, Icarus, you may also remember, flew too near the sun with waxed wings Daedalus had designed.)

According to this legend, Minos’s wife, Queen Pasiphae, who came from the city of Athens, slept with a bull (there’s a lot of bull in this tale) who was sent to her by Zeus, the top God of ancient Greek mythology. After this, Minos’ son went to Athens to take part in the Panathenaic Games (something like the Olympics) and was killed by the very bull that had impregnated Minos’ wife. Understandably pretty angry, but mindful that Zeus was not a god to be trifled with, Minos captured the Minotaur (his stepson) but didn’t have it killed.

Instead he placed the bull-man in the labyrinth. From Athens, Minos every year demanded seven young men and women from that city as a punishment, and also to avoid a plague (great excuse) and confined them to the labyrinth, where the Minotaur found them and ate them. Pretty gruesome story, but that’s the type the ancient Greeks loved to tell to their children.
Minotaur, half man – half bull
Anyway, long story short, Theseus in the third year decided to take on the Minotaur by offering himself up. After entering the cave, and using dental floss given to him by Ariadne, daughter of Minos, who had fallen for him and was a dental hygienist by trade, he laid down a trail that he could follow out later. So, kids, believe it or not, Theseus confronted the Minotaur and killed him and escaped from the labyrinth by following the trail of floss. That’s not where the story ends, but you’ll have to look the rest up.

It’s complicated.