Science Fair Projects Research
Tooth Decay and its Causes

Tasmiha
Age: 16
Illinois, USA

If one knows the structure and contents of a typical tooth, it will be much easier to understand tooth decay.

What exactly is tooth decay someone might ask? It is another name for having a cavity. In a tooth, there may be a portion of the tooth where it is eroding. Because much of the mineral has been dissolved, the result is a hole, which is also known as a cavity References on Traumatized Teeth (Academy of General Dentistry, 1998-2004 [Online]).

If one munches upon his or her favorite sweets, one may not realize it but they might be taking in more sugar than one actually needs. The average American eats 147 pounds of sugars each year. And the fact that, an average American who is 17 years old has more than three cavities is not a coincidence. Gradually, these foods that contain sugar attract germs. As the germs build up, plaque is formed.

Plaque is a light covering which grows between teeth and the edges of gums. It can also form from natural bacteria located in your mouth. Plaque has bacteria, which produces acids that feed on bits of food left in the mouth. They mainly feed on carbohydrates (sugary foods). The acid beginning from the plaques eats away the enamel, leaving a hollow space, which is called a cavity or in dental terms, it is called caries. If plaque isn’t moved normally by brushing, it can form tartar or calculus. It also dissolves the calcium of the tooth. If the decay reaches the pulp, it will eventually reach the nerves. That is the chief cause of pain References on Traumatized Teeth (Ward, 1986 p.19).

There are two types of bacteria known as Streptococcus mutans and Streptococcus gordonii, which are known for inciting cavities. Streptococcus mutans has a stronger ability for starting cavities more in sucrose, but it is weaker in corn sweeteners, which are fructose. Sucrose is a natural sugar found in various foods. Fructose is also found naturally in honey, nectar, etc. However, it is much sweeter than cane sugar and it’s used for people with diabetes. Streptococcus gordonii is mainly found in soft drinks References on Traumatized Teeth (U Conn Health Center, 2001 [Online]).

Now that you have background information about tooth decay and its causes, let's read about prevention of tooth decay.