Team:Northwestern/Project
From 2013.igem.org
Northwestern iGEM
overall project
Background
Oral health is one of the most overlooked aspects of health care in the world. According to the World Health Organization, 60-90% of children worldwide have dental cavities, while they are present in nearly 100% of adults1. Tooth decay and cavity development are a direct result of the plaque that accumulates in the mouth after meals. The plaque is a biofilm composed of a number of different types of bacteria native to the oral biome2. These bacteria, in particular Streptococcus mutans, secrete lactic acid as a result of sucrose metabolism, and the resulting drop in pH causes demineralization of the enamel3. Since the plaque traps the lactic acid on the surface of the teeth this pH drop takes place in direct contact with the enamel at a significant concentration. This pH drop is most prevalent directly following mealtimes. The threshold pH at which demineralization occurs is 5.5. The figure below shows that the surface of the enamel can spend nearly 5 hours a day exposed to pH below the demineralization threshold, thus this is a serious problem that provides motivation for this research.
![](https://static.igem.org/mediawiki/2013/f/fe/Mouth_pH.png)
The Stephan Curve4, depicting pH fluctuation in the mouth over 24 hours.