MK dental care welcomes questions from our patients about what causes dental decay, so feel free to speak to any of us at your next appointment.

What causes a cavity?

By Kimberly A. Loos, D.D.S.

By understanding the cause of a cavity, patients might be better able to prevent them. Cavities are actually caused by a chain of events that start when food is allowed to remain on your teeth. The worst culprit is sugar because it is easily digested by the bacteria that naturally live in your mouth. However, any food left on the tooth surface long enough will eventually become sustenance for the bacteria. Once the bacteria, a component of plaque, digest the food, they produce an acid. It is this acid which eats away at the enamel (outer layer of tooth) eventually causing a "hole" in your tooth. The best way to prevent cavities is by practicing good oral hygiene. Plaque also causes gum disease, which is a major cause of tooth loss in people over the age of 35. So, there are now at least two good reasons to brush and floss your teeth regularly!

Tooth enamel consists of a substance called hydroxyapatite. Dissolving hydroxyapatite is called demineralization, and its formation is called remineralization. In the mouth there is an equilibrium between these two processes which is established even with healthy teeth.

Do you know any chemistry? When sugar ferments on teeth, hydrogen ions are produced that upset the equilibrium between demineralization and remineralization by combining with hydroxide ions to form water. Removal of hydroxide ions causes more of the hydroxyapatite to dissolve, resulting in tooth decay. Fluoride helps prevent tooth decay by replacing the hydroxide ions in hydroxyapatite. The resulting chemical compound is very resistant to acid attack!

Tooth Erosion is a major problem for Children and Adults
This Tooth Damage is caused by Fizzy Drinks

Diet and dental disease

Nutritional status affects the teeth pre-eruptive, although this influence is much less important than the post-eruptive local effect of diet on the teeth. Deficiencies of vitamins D and A and protein-energy malnutrition have been associated with enamel hypoplasia and salivary gland atrophy (which reduces the mouth’s ability to buffer plaque acids), which render the teeth more susceptible to decay. In developing countries, in the absence of dietary sugars, under nutrition is not associated with dental caries. Under nutrition coupled with a high intake of sugars may exacerbate the risk of caries.

There is some evidence to suggest that periodontal disease progresses more rapidly in undernourished populations; the important role of nutrition in maintaining an adequate host immune response may explain this observation. Apart from severe vitamin C deficiency, which may result in scurvy-related periodontitis, there is little evidence at present for an association between diet and periodontal disease. Current research is investigating the potential role of the antioxidant nutrients in periodontal disease. Poor oral hygiene is the most important risk factor in the development of periodontal disease. Under nutrition exacerbates the severity of oral infections (e.g. acute necrotizing ulcerative gingivitis) and may eventually lead to their evolution into life-threatening diseases such as noma, a dehumanizing oro-facial gangrene.

5. Population nutrient intake goals for preventing diet-related chronic diseases