What Causes Dental Cavities?
Specific bacteria such as Streptococcus mutans cause cavities.
These bacteria are aerobic meaning they require oxygen to survive; having a dry mouth increases the chance for cavities.
Cavity causing bacteria are different than the bacteria that causes gum disease, which live in an anaerobic environment. Both of these bacteria can be passed from person to person.
Plaque, is also known as Biofilm.
A microbial biofilm is a layer of prokaryotic organisms which adhere to a surface and are coated with a polysaccharide layer.
The biofilm increases the prokaryotic cells survival through increased defense, availability of nutrients, cellular communication, and the ability to transfer genetic material to each other.
A polysaccharide is composed of more than one sugar molecule. Carbohydrates, Starch, Cellulose, and Glycogen are polysaccharides.
How the cavity is formed
Underneath the plaque, the bacteria produce acids as a by-product of their metabolism.
The acids produced by the bacteria break down tooth structures, this is also known as demineralization.
Once the demineralized tooth structure grows into an advanced bacterial colony, it is than defined as a cavity.
How to Prevent Cavities
For further reading see the source below from the American Dental Association (ADA)
Tackling Tooth Decay
My education consists of a Bachelor of Liberal Arts Degree in Business Administration & Art. Since then I have taken classes in chemistry, organic chemistry, biology, physics, and microbiology to pursue a career as a dentist; I studied to apply for dental school to become a dentist but was unable to pursue it.