When tooth decay-causing bacteria convert sugar and starch into acids that dissolve the calcium in tooth enamel, cavities are often the result. But as the local concentration of calcium increases locally during dissolution, the environment becomes more hostile to bacteria.
According to an article published in Science Daily, new research from scientists at the University of Basil sheds light on how bacteria survive this inhospitable, calcium-rich environment.
Their research points to a helping hand from extracellular polysaccharides (EPS)—complex carbohydrates that build a layer of additional bacteria from sugar residue. EPS acts as the biofilm or “scaffolding” for the bacteria to cling onto dental plaque.
The researchers demonstrated that EPS contains calcium-binding sites that integrate the calcium from their environment into the biofilm where the bacteria resides. As the biofilm becomes richer in calcium, the bacteria build a tolerance to its harmful properties and adapt.
Through the process of calcium integration into the biofilm, EPS also inhibits the enamel from securing any free calcium for regrowth, further contributing to the development of cavities.
In other words, the very substance that helps harmful bacteria survive and cause cavities also takes the materials needed for the tooth to protect and rebuild itself.
Research like this will help scientists further understand the process of how cavities form and hopefully provide us with valuable new insights into how to prevent them.