So we keep hearing about these holes that form in our teeth, which are known as cavities.We know that we get cavities when we don’t brush our teeth frequently enough or properly, but what causes cavities?

What is a cavity?

Cavities are also referred to as dental caries or tooth decay. They are structural damage, such as holes, formed on our teeth.

What causes a cavity?

Remember when we talked about how there are bacteria in our mouths, some of which are selfish? Well, two selfish bacterial species, Streptococcus mutans and Streptococcus sobrinus, love to eat the food residues on our teeth. This food allows them to grow quickly and reproduce, which can lead to plaque formation, which is a problem.

But these bacteria, in addition to other bacterial species that feast on the food residues on our teeth, are also responsible for the formation of cavities. When they eat the sugars that we haven’t swallowed or digested, the bacteria oxidize the sugars; they break the sugars down into smaller molecules in their cells in order to obtain energy. The products of this break down of sugars are high acidic. They are so acidic that our teeth are unable to withstand it, and are consequently damaged slowly. This leads to the formation of structural damages and, in the case of cavities, holes!

Brush your teeth at least twice a day!

The recommended frequency of brushing your teeth is twice/day, while its duration is recommended to be approximately two minutes. If you don’t brush your teeth properly by getting every area of your teeth or if you don’t brush your teeth frequently enough, then your chance of forming cavities increases significantly. Sugars, food residues and bacteria will accumulate on the surfaces of your teeth without a good brushing routine. The bacteria will then be able to use those sugars to grow, which will result in the production of more acid, which leads to more structural damages to your teeth.


Remember when we talked about fluoride in toothpaste last week? Well, toothpastes that help to prevent cavities contain fluoride as it helps to promote strength in your teeth. This increase in strength will allow any [hopefully minimal] acid production to have a lesser effectiveness, meaning there will be less damage!

So brush your teeth often, properly with a dash of toothpaste and SMILE.



So, last week, we talked about the importance of brushing your teeth. This week, we’re going to talk about how toothpaste helps in getting rid of those bacterial plaques and even, in situations where you don’t have much else to resort to, treating acne. So how does toothpaste help us in the fight against bacteria?

What’s in toothpaste? 

According to Colgate and The US National Institute of Health, there are two main components to toothpaste:

Sodium fluoride 

Fluoride is the most well-known ingredient of toothpastes. But what does it do and how does it work? Sodium fluoride inhibits the decay of tooth enamel and promotes enamel growth! In fact, it helps make your teeth stronger when it helps remineralize them. However, once you have a cavity, the fluoride cannot help rebuild the enamel.


Triclosan is an antibacterial agent. This component works against all sorts of bacteria and is often used in disinfectants. Even though you brush your teeth, and likely dislodge a majority of the bacteria on your teeth, Triclosan acts as a second line of attack against the microbes. This helps ensure that your teeth are sparkling without you having to worry pesky plaques forming. Thanks Triclosan, you’re the best!

Toothpaste and Acne?

Triclosan is the reason why toothpaste has the potential to work against the acne induced from bacterial growth clogging your pores – it will kill the microbes, preventing further growth! But again, it’s best to use the other treatments in a regular fashion. Toothpaste treatments are a last resort, if even a resort.

Why shouldn’t we eat toothpaste?
Fluoride, while helpful to our teeth in that it prevents cavities by making our teeth stronger, is hazardous to our bodies at high dosages. The reference daily intake of fluoride is 4mg for people over the age of 4, which isn’t that much fluoride.
In fact, we can get that much fluoride from drinking 1 liter of tap water, depending on where you live.
You see, fluoride was introduced into our water to promote dental health (Hurray for you tap-water drinkers!). But the United States Environment Protection Agency has set a maximum goal of 4mg of fluoride/L of drinking water. If a city were to violate that goal, you would be at risk after drinking a liter of water just because you’ve gone beyond your reference daily intake for fluoride.
What happens when you have too much fluoride in your system?
When you’ve ingested a large amount of toothpaste, you may develop stomach pains and intestinal problems for the day. You could also experience some of the following:
  • Weakness
  • Vomiting
  • Tremors
  • Diarrhea

Worst case scenarios:

  • Seizures
  • Heart attacks
  • Difficulty breathing
  • Slow heart rate

But, again, you’d have to ingest a LOT of toothpaste. And if you ingest a lot of toothpaste over your lifetime, or even just a lot of fluoride, you increase your chances of bone fractures.

Ironic, right? What we thought to help us strengthen our teeth also has the potential to weaken our bones. So remember, little in this case is more. And don’t eat your toothpaste, no matter what flavor you bought.

Additional Sources: Seeley, R.R., Stevens, T.D., and Tate, P. 2008. Anatomy and Physiology (8th ed.). pp. 935. New York: McGraw-Hill.

Brushing Your Teeth

It’s at the start of your day and, hopefully, before you shut your eyes for bed when you brush your teeth. But why do we need to brush our teeth? Sure, the ‘scary’ dentist tells us to. Our parents scared us into it too; except when I was smaller, we were given sticker books that we got to fill for every morning and night we brushed our teeth (stickers=fun!!). But what’s the deal with brushing our teeth?

Why do we brush our teeth?

Alright, you smart alecs, I know what you’re going to say: Because it’s hygenic, Meera! Okay, yes, you’re all right, it is hygenic. But how? What are we trying brush off?

Why do we really brush our teeth?

There are several species of bacteria in our bodies, helping us perform various cellular processes but there are also some bacteria who are just selfish. There are two notable species of bacteria in our mouths; Streptococcus mutans and Streptococcus sobrinus. Both of these bacteria are greedy.

After we eat food, the food residue(sugar) on our teeth act as a buffet of sorts for these two bacteria. The by-products of this consumption of sugar are acids, which break down the enamel of our teeth. These bacteria also grow, thanks to the supply of sugars that they’ve received; their growth in a thin layer on our teeth is what we call the formation of plaque. Plaque can lead to gingivitis, which is a disease of the gums which makes them inflamed and sore.

It’s important to remember that it’s the sugars that we eat that provides bacteria with the nutrients to grow and multiply. So the more sugar we eat, the more food we’re giving to the bacteria.

So we really brush our to break down the bacterial plaque that forms on our teeth after we eat. This is why it’s necessary to brush at least twice a day; with all the sugar we consume in one day, it’s necessary that we prevent bacteria from forming plaques.

And that is how brushing your teeth is a form of hygiene. Next week, we’ll talk about how toothpaste works to help us brush our teeth.