So, what is a cavity anyway? 

Where do we find them? Where do they come from and how can they be prevented?

Your dentist calls them dental caries and we spend our careers trying to stop them from spreading. Think about it: have you ever been to a visit with the dentist without them and the hygienist reviewing proper oral hygiene. It's the sound of a constant drumbeat - brush twice a day for 2 minutes... make sure you floss daily… do you use a fluoride rinse?… and on and on and on. I often joke with my patients that we must be the only professionals that are trying to put ourselves out of business!

Let's face it, most of us have had at least one cavity, even those that heed our warning and follow a good home-care regimen, but following your dentist's recommendations will vastly reduce your risk and keep us from having to pick up our drill.

Here are 5 facts about cavities that you may not have known:


1. A cavity is a bacterial infection
On the most basic level a cavity is simply an acid burn. You may have heard that sugar causes cavities, and that is indirectly very true. The direct cause is the production of acid from bacteria that we all have in our mouths. The main culprit is one call streptococcus mutans, but there are others, and depending on the patient they play different rolesThis acid begins to erode the enamel, which is the hard outer layer of your tooth. This small hole that starts becomes more difficult to clean, which starts a downward spiral of greater collection of bacteria and deepening of the cavity. Where does this acid come from? It's the byproduct of the sugars and other carbohydrates that are eaten by the oral bacteria after you have your meal or snack.

These bacteria form colonies that build up to form plaque. Dentists call this a biofilm, which is nothing more than a huge group of bacteria held together by their own sheer will and a few other main ingredients, often produced by the bacteria themselvesSo imagine the number of bacteria that needs to be present for you to be able to see it! These microorganisms reproduce very quickly (some create an entirely new generation in about 20 minutes!), so brushing twice and flossing once daily helps to reduce these numbers, allowing you to contain their spread.

2. Your teeth may be constantly under attack
Since we covered the bacterial production of acid with respect to the foods we eat, we can take that a step further. To get you up to speed without giving you high school chemistry nightmares – a greater acid concentration means a lower pH. Each time we eat, the acid content increases and therefore the pH in our mouth falls. People that eat more often, especially those that frequently snack on sugary foods, will have their oral pH in the cavity-producing danger zone more frequently. This has been found through research to be below a pH of 5.5. This fluctuation is know as the Stephan Curve, which is seen below. It is best controlled with proper, brushing, flossing and rinsing habits to reduce the sugars and bacteria that may have collected. 



There are some foods and beverages, usually taken in between meals, that are tooth killers. These will ensure that your teeth spend overtime below the safe pH level: Soda (or any type of carbonated drink), sports drinks, energy drinks, juice (especially citrus), sugary chewing gum, and, of course, candy. At CrossKeys Dental, we don't ask that you change your life, but that you understand how Stephan's Curve works and realize the importance of oral hygiene. 

So, a nutritionist and a dentist have different opinions with regard to timing. When looking at Stephan's Curve, it makes more sense to eat all of your food in fewer sessions. For instance: Halloween just passed. From a dentist's view, your teeth would be safer if you ate the entire bag of candy in one sitting rather than spreading it over several days. Of course, you might end up with a stomach ache... but the acid attack on your teeth would be limited to one event rather than many.

3Cavities are contagious
Like any infection, dental caries can be spread from person-to-person or tooth-to-tooth. Just like when you pass a cold virus to your coworkers, you can pass your oral bacteria to other people. This can happen easily if you are not taking good care of your mouth. It even means that sharing a spoon or licking a baby's pacifier can be bad news. In the image below, you will see what many dentists call “kissing caries”. It sounds a lot cuter than it is... It's actually the spread of the dental infection, or cavity, from one tooth to another. Here you see it happening several times.




4Dental caries is the most prevalent childhood disease
As reported by the Centers for Disease Control and Prevention, “Although dental caries are largely preventable, they remain the most common chronic disease of children aged 6 to 11 years and adolescents aged 12 to 19 years. Tooth decay is four times more common than asthma among adolescents aged 14 to 17 years. Dental caries also affects adults, with 9 out of 10 over the age of 20 having some degree of tooth-root decay”. This was reported in the CDC's Vital and Health Statistics report in 2007. Here are some key facts to consider:

  • By age 15, approximately 60% of all adolescents will have experienced tooth decay (CDC, 2007)

  • An often cited study estimated 51.7 million school hours are missed annually by school-aged children because of a dental problem or visit (Gift, 1992)

  • In 2009, the total dental expenses for U.S. children aged 5–17 years were approximately $20 billion (US Department of Health and Human Services; 2013), accounting for 17.7% of all health-care expenses among this age group (US Department of Health and Human Services; 2012)

It does not have to be this way. Dental cavities are largely preventable with good education leading to proper hygiene.

5. A cavity doesn't usually hurt.
I will often reveal to someone that they have a cavity, and I will show it to them on our HD monitor, and I hear “But I don't feel anything”. It takes a long time for a tooth to start bothering you due to a cavity. In fact, if you have a toothache due to a cavity (lots of things can cause your teeth to hurt), it's probably too late for a simple filling. When you have spontaneous pain or sensitivity to temperature, especially heat, it's likely time for a root canal. It is recommended to have your cavities repaired when they are small so that you can avoid additional, costly fees to save the tooth.

As an old professor in dental school used to say: We need 4 things to cause a cavity– teeth, carbohydrates, time and bacteria. Of course, getting rid of your teeth isn't the solution, we can't stop eating and we have yet to figured out how to stop time. The only factor that can be controlled is the bacterial load. So why are you still reading this? Have you brushed your teeth yet?


CrossKeys Dental is located at 110 CrossKeys Office Park in Fairport. Dr. DuPre` and Dr. Badali provide comprehensive family dentistry and are always welcoming new patients. Visit us at for more information. Written by Vince Badali, DDS