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Why Do Cavities Form?

Why cavities form is an interesting topic that is both useful & informative. In this issue, we’ll be discussing the science of decay formation while giving you some suggestions to prevent cavities from forming in your own mouth.

Decay formation is caused by what dentists refer to as “demineralization.” This is a process that occurs when a tooth is exposed to an acidic environment of pH 5.5 or below. The number 5.5 is an approximate value that varies depending on the current condition of a person’s mouth (e.g. how many Mountain Dew sodas a person gulps, etc.), which can lead to the level of calcium and phosphate in their saliva. The physical characteristics of a person’s tooth enamel (its resistance to decay) can even vary on a tooth-to-tooth basis as determined by the building blocks available during its formation.

1) “Demineralization”

The acidic environment damages the tooth’s hard tissues (enamel and dentin), so that there is a depletion of leaching mineral content (primarily calcium and phosphate ions). Hence, the term “demineralization.” Note: Normal conditions for the mouth are neutral (around pH 7). Routine beverages like coffee have a pH well below 5.5 and can also contribute to the demineralization process.

2) Acids that cause decay are bacterial waste products.

Specific types of bacteria like [streptococci mutans & lactobacilli] produce acid, which causes tooth demineralization. The bacteria that cause cavities are living organisms. They consume food and the wastes that these types of bacteria create are very acidic (having a pH of 4 and lower).

chemistry of tooth decay

3) Bacteria steal our food

The primary food source for cariogenic (cavity-causing) bacteria is dietary sugars. This includes sucrose (table sugar), glucose, fructose, lactose, maltose, and cooked starches. The bacteria digest these sugars via a process called glycolysis, and produce acid.

4) Tips for preventing decay

Within minutes of consuming a sugary meal, oral bacteria start to produce acids that cause tooth decay. Research shows that it typically takes between 30 and 60 minutes for the mouth to return to its original status. So, the less sugar you consume and the less time you allow those sugars to remain in your mouth, the less exposure your teeth will have to bacterial acids.

» Minimize how long sugars are allowed to remain in your mouth. Brush and floss, or at least rinse with water, promptly after every meal or snack.
» Substitute xylitol for table sugar. This natural alternative helps to prevent cavities by e!ecting the types of bacteria that create it.
» Keep the level of plaque in your mouth to a minimum. The more cavity-causing bacteria that are present, the greater the amount of acid that’s produced.
» Brush and floss often and effectively. Take the time to be thorough with your brushing and $ossing AT LEAST 2 MINUTES TO ALLOW THE Fluoride in toothpaste time to work!!! The places where you do not clean well are the areas where cavities will be most likely to form.

When it comes to causing tooth damage, there’s nothing unique about the acids that bacteria create. Anything that promotes acidic conditions in your mouth assists the same demineralization process, and that includes many of the beverages that people routinely consume.

5) Why plaque is so bad

Dental plaque not only provides a home for bacteria. It also acts as a medium that holds the acid they produce directly against a tooth’s surface. The acid that’s most instrumental in causing demineralization is the type which seeps through the plaque and down to the tooth’s surface. The thickness of dental plaque tends to act as a protective covering that helps to shield the acid from being washed away. Over time, saliva will work to penetrate through the dental plaque and create its neutralizing effect. Well, as usual I’m “Full of It” … good information that is! I hope this will help prevent tooth decay for you & your family. We have the technology & the know-how to prevent problems before they occur!

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Dr. Eric Vanek, d.d.s

Eric has been a practicing dental surgeon for over 20 years and is the owner of Vanek Dentistry, a family dental practice in Costa Mesa, CA.

Published January 31, 2020. Updated June 5, 2023