Cavities occur as a result of tooth decay. Tooth decay is the destruction of tooth structure. Tooth decay can affect both the enamel (the outer coating of the tooth) and the dentin (the inner layer of the tooth).
Tooth decay occurs when foods containing carbohydrates (sugars and starches) such as breads, cereals, milk, soda, fruits, cakes, or candy are left on the teeth. Bacteria that live in the mouth digest these foods, turning them into acids. The bacteria, acid, food debris, and saliva combine to form plaque, which clings to the teeth. The acids in plaque dissolve the enamel surface of the teeth, creating holes in the teeth called cavities, or caries.
Who Gets Cavities?
Many people think cavities only affect children, but changes that occur with aging make cavities an adult problem too. Recession of the gums (a pulling away of gum tissue from the teeth), often associated with an increased incidence of gingivitis (gum disease), can expose tooth roots to plaque. Also, sugary food cravings in pregnant women can make them more vulnerable to developing cavities.
Decay around the edges of cavity fillings is also common in older adults. Because many older adults lacked the benefits of fluoride and modern preventive dental care when they were growing up, they often have a number of dental fillings. Over the years, these fillings may weaken and can fracture, allowing bacteria to accumulate in the tiny crevices causing tooth decay.
How does your dental cavity get started?
The bacteria in your dental plaque converts the sugar that you eat into the acid through the process known as fermentation. In biochemistry, it is estimated that one glucose (sugar) molecule can ferment into two molecules of pyruvic acids.
Bacteria + Sugar ------> Acid
When the acid contacts the outer surface (enamel) of the tooth, it dissolves the enamel, forming a hole. This hole is called a cavity or dental caries. Superficial dental cavities are those that occur within the outermost enamel layer of the tooth, and they require a close observation from our dentist. If the cavity grows into the softer inner layer (dentin), the tooth needs to be restored with a filling.
Acid + Tooth surface ------> Cavity
As the cavity becomes bigger and penetrates through the dentin layer, it gets into the nerve chamber (pulp) at the center of the tooth. This causes a toothache. A toothache may be treated with a root canal (root canal endodontic) therapy or an extraction.