Why do you brush your teeth?

Surprised to hear that tooth brushing doesn’t prevent cavities?

Abstract: Surprisingly perhaps, but most people would answer that question incorrectly as we’ve all been taught that we brush our teeth to prevent cavities – but we don’t – there’s no evidence that it does.

Whilst it may not be the only anti-cavity measure – it does however reduce bacterial load, promote fresh breath and helps prevent gingivitis and later gum disease, (periodontal disease). See below for toothpastes.


Certainly good enough reasons to keep up the good work. There’s also some evidence that the prevention of periodontal (gum) disease, may reduce the incidence of heart disease (CVD: Cardio vascular disease).

Equally there is evidence that antioxidants may be of use when it comes to the management of gum disease, after the importance of careful cleaning and removal of plaque from all areas of the mouth of course.

What causes tooth decay (caries or cavities)?

Sometimes we take our teeth for granted, “be true to your teeth, or they’ll be false to you,” a little bit of dentist’s humour. Most people know that sugar causes cavities but what is often not considered it the Venn diagram from which it works.

A cavity is caused by bacteria that build a stick residue to protect themselves called plaque. They feed on carbohydrates in oral fluids (which mostly comes from the diet) and produces acids which ‘de-mineralizes’ the tooth, whose enamel is largely mineral (calcium) thereby causing breakdown and cavities.

There are three factors that combine to cause a cavity: bacteria, carbohydrates, and a tooth.  If we control any of these factors, we’ll never get a cavity again. Unfortunately, it would be very difficult to remove only one offending area, so we need to address all three.

What role do Bacteria play in producing dental decay?

Everyone has bacteria in their mouths. You can’t get rid of it completely, nor would you want to, bacteria form a large part of the body and all is well when there’s balance. That’s what needs to be addressed.

It’s true that if we reduce the number of bacteria in our mouths by properly brushing and flossing, then they won’t be able to accumulate enough acid to actually cause a cavity.

In actual fact some of the areas where cavities are most likely (in the grooves and between the teeth) you can’t reach with a toothbrush. That doesn’t mean you shouldn’t brush your teeth.

Strangely enough, you use a toothbrush to prevent gum disease, not tooth decay. It also aids in preventing bad breath of course.

Toothpicks are useful but still can’t clean the contact where one tooth touches the next, it’s below this (the ‘approximal surfaces’ – those surfaces which form points of contact between adjacent teeth and are the second most cavity prone after the grooves in the tops of the teeth.) that many cavities start.

Also, unfortunately a harder and more demanding area for the dentist to prepare and place a filling.

Use care when you use tooth picks, when pushing them between the teeth (gently), when working from the outside (which most people will) angle the tip up slightly when cleaning the lower teeth and slightly down when you’re clearing the upper teeth, as it saves digging the tip into the delicate tissues between the teeth.

The bacteria in plaque double in number about every five hours. If you don’t brush for 24 hours you will go from about 2 billion bacteria to 65 billion bacteria, approximately.  

When you brush your teeth, you are reducing the bacterial “load” of the mouth. Therefore, you are not brushing to get rid of food particles. Ideally (think about the diagram) you’d brush and clean the surfaces of your teeth BEFORE not after meals. It’s OK to brush after breakfast though, providing you brush before starting the day, right?

Flossing isn’t difficult as difficult as people make out. It doesn’t take a long time, however, if in doubt, you need to have someone show you – even if you’re an adult! Hate to say this, but after 40 years as a dentist, most people don’t floss properly.

We can also change the quality of cavity-causing bacteria. Fluoride toothpaste, alcohol-based mouthwashes, and xylitol chewing gum all inhibit those bad bacteria.

Also, eating cultured yogurt may put good bacteria in your mouth that compete for space to block out the bad bacteria. I don’t really consider those the answer though, a bit too invasive for me.

Beware carbohydrates – specifically highly refined carbohydrates

Here’s the answer.  Carbohydrates, especially sugars like sucrose, fructose, and lactose, feed the bacteria that cause cavities. Sadly, dentists also see more cavities in “pop” drinkers as these “soda” are crammed with highly refined carbohydrates.

Incidentally, keep an eye on “health” drinks and those intended to return electrolytes, minerals and salts back in (hydrating sports drinks) as they may be quite acidic and drunk, like sodas, quite frequently. Those soda drinkers at risk, are people that drink four or more sodas a day.

Refined carbohydrates (sugar)  do more damage to the teeth if you drink or snack between meals for two reasons, first they stay around the teeth, there’s nothing to wipe/rinse them off, nor equalize or deactivate the acids so formed.

The other reason is that when you eat sweets or candies, or high sugar foods, the acid levels increase and the pH of saliva drops (acid) and takes time to recover.

If you eat sweets or candies between meals, the saliva doesn’t have time to balance toward neutral. If you limit sweet (sugar containing) foods to mealtimes, you’ll do little damage to the teeth, all other things being equal.

When our own kids were younger, we lat them have any sweets or candies after their meal while they were still at the table. Cruel eh? They didn’t get a single cavity.

So Enjoy a sweet treat as part of a meal instead. If you drink a soda without a meal, rinse your mouth with water as soon as you finish the soda, so it doesn’t have time to soak on the teeth.

Cola soda has a pH of 2.8. (Put a coin in a glass of cola overnight and in the morning,  you’ll see metal starting to dissolve – scary eh? Tooth enamel starts to dissolve when pH drops below 5.5. That means that if you drink multiple sodas per day, they may be causing cavities by directly dissolving the teeth without the need for bacteria to change sugar to acid.

If you limit the sugar you eat, you’re also limiting the sugar that gets to the bacteria. Sugar can be bad for your overall health, not just bad for your mouth. A diet with lots of vegetables and plenty of water is also great for the health of the mouth.

The tooth and its vulnerability to acid attack

The teeth are the third piece of the puzzle that cause cavities. While it’s true that someone who has no teeth will never get a cavity, a denture is not recommended unless there is no other option. Would you cut off your hand and use a prosthetic to avoid a hangnail? Of course not. The idea to “just pull them all and be done with it” is just as ridiculous.

How then do we make the teeth more resistant to cavities? Genetics helps. It’s true that some people have stronger, thicker, denser tooth enamel than others.

If you think you have “bad genetics,” or “weak teeth,” let me assure you – even the weakest enamel I’ve ever seen was still harder than bone.

Enamel is the hardest substance in the body. Keeping your teeth clean will prevent cavities, even if you have “weak enamel.” Bad genes is not a catch-all excuse for cavities.

Fluoride helps make enamel denser. If the enamel is denser, it’s going to take more acid to dissolve it. Ideally kids should drink water fluoridated to one part per million while the teeth are developing. After the teeth have developed, daily fluoride toothpaste helps to demineralize enamel that may have been damaged from acidic foods or bacteria acid.

Saliva is an amazing substance. It’s not just water. Saliva has antibodies, proteins, enzymes, and minerals that act as a buffer to protect the teeth from acid. Now, saliva flow naturally goes down at night, so this would be the worst time to have a snack. I had a patient who would wake up at night with a dry mouth and sip on sweet tea.  Don’t do that! He had new cavities every time he came in for a check-up.

Fissure sealants are  a great way to protect teeth. Some natural grooves are too narrow and deep for the toothbrush bristles to get in there and clean them out. Sealants make teeth smooth and easy to clean. No grooves for bacteria to hide in.

Another way to strengthen teeth is to use fluoride. As a public health measure it appears to have advantage but must therefore be considered as mass medication (along with chlorine and everything else).

I don’t believe that Fluoride is necessary to prevent cavities although I do believe that care, life style choices and effort is – sometimes that seems harder than fluoride.

Non F – Forever bright tooth Gel – CLICK TO ORDER

Follow these tips and never get cavity free and be happy.

Several toothpastes DO NOT CONTAIN FLUORIDE and for those people that wish not to add extra F to their input, foreverliving.ca products make and distribute some good products including a non-fluoride toothpaste

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