|MadSci Network: General Biology|
MN: I don't know your grade level, so I'm going to assume you are a high school student. The effect of sugar on teeth is to supply food for bacteria which produce acids when they grow. (Sugar is chemically close to many organic acids, and living things convert sugars to acids and energy as part of their food cycles.) The acids produced from sugar metabolism eat away the enamel on teeth. The acids produced include lactic acid, citric acid, propionic acid and acetic acid. The bacteria involved include Streptococcus species (e.g., mutans) and lactic acid-forming bacteria. For there to be a problem, the following things must be present: 1) sugar, 2) the right kind of bacteria, 3) time for the conversion. To prevent tooth decay, you must: 1) avoid sugars and starches (similar to sugars), 2) remove the bacteria and acids (by brushing), 3) slow the growth of the bacteria, or 4) harden the enamel (by flouride treatments). Things to investigate would include: 1) frequency of brushing, 2) amount of sugar, 3) time elapsed between eating sugar and brushing, 4) effect of antimicrobial mouthwashes, 5) effect of fluoride in toothpaste, water or treatments. Listerine is a brand of mouthwash most advertised as antimicrobial. Almost all common toothpastes include some form of flouride. Chewing gums replace sugar with sorbitol or other sweetener to avoid acid generation. See http://www.lazerdontics.com/decay.htm for a summary. If you wish to search the internet, I would suggest using "sugar AND caries" as a starting point. An interesting science experiment would be to measure the acid formation and effect on teeth (or apatite, the mineral in enamel) by using different sugars (sucrose, dextrose, sorbitol, starch).
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