Cavities Are Caused by Bacteria

by: Dr. Tom Swanlund

Cavities, simply, are openings through the protective structure of the tooth/teeth caused by infectious bacteria. The protective outer surface of the tooth is enamel. At times, due to wear and disease, other areas of tooth structure may be exposed called dentin and cementum. Enamel is the hardest/strongest structure in the human body, even stronger than bones. Cementum and dentin on the other hand are softer and when exposed to the oral cavity can form soft areas or cavities at a much faster rate. Enamel, cementum, and dentin all have a similar purpose; to protect the pulp of the tooth which is the area where the nerve and the rich blood vessels that feed the tooth reside.

Cavity formation can take some time. Initially, the rise in the acid level due to cavity-causing bacteria results in the breakdown of the external portion of the tooth structure. This breakdown either continues with further degradation of the tooth structures or can be halted and reversed through the application of fluoride and the buffering/remineralization effect of saliva.

Increased acidity of the mouth occurs through the consumption of carbohydrates, which when left on or around the teeth, is consumed by infectious bacteria which secrete their by-products (bacterial waste). The bacterial waste can raise the acidity level and increase the chance of cavities forming on the teeth. Good home care is important to rid the teeth of food so this process cannot begin.

Prevention of cavities starts with brushing three times a day for a minimum of two minutes with fluoride toothpaste and flossing once a day. If a person is at high risk for cavities, a higher concentration of fluoride toothpaste or an added daily fluoride rinse is a good idea. As well, many medications which people take have a side effect such as dry mouth, which raises their chance of developing cavities, thus homecare is vital for prevention.

If your dentist has told you that you have a cavity, it is important you attend to it. In the early stages, a cavity stays within the enamel; but once it travels to the underlying dentin, it can spread rapidly. Once the cavity goes through the dentin and into the pulp, it can cause infection, inflammation, and discomfort. When the pulp becomes inflamed and infected, many times it will require a root canal (removal of the pulp and nerve of the tooth). Catching a cavity in the early stages is the key.

In order to treat a cavity, the dentist will remove the soft area (cavity) of the tooth and replace it with a filling. The filling will take the space where the cavity was and protect the inner portions of the tooth, just as the enamel once did. It is important to keep the area around the filling as clean as possible to prevent new cavities from forming.

In some areas the water is not fluoridated so the use of fluoride toothpaste is vital in prevention of decay. According to the ODA, "Tooth decay is the most common chronic childhood disease, one of the leading causes of absences from school, and only a small percentage know that it’s an infectious disease." Prevention of oral disease goes a long way.
Brush, floss, and rinse for oral health!