Within dental plaque, the bacteria species called Streptococcus Mutans will take carbohydrates, especially sugar, and create an acidic byproduct. The acid produced by S. Mutans has two roles in the production of cavities. First, the acid demineralizes the tooth so bacteria can invade the tooth and cause further demineralization. Once the bacterial demineralization is deep in the enamel, it becomes sticky, dark, and shows as a shadow on x-rays. Second, the acid will kill off beneficial bacteria within the plaque, making way for more Streptococcus Mutans to proliferate. This process is a vicious cycle because the more acid Streptococcus Mutans produces, the more abundant it becomes, creating more acid. Once the acid pH of plaque drops below 5.5, the tooth will start to demineralize.

It should be obvious now that sugar and Streptococcus Mutans are what cause cavities. Now that you know the process, click on this link for the best daily oral hygiene routine to prevent tooth decay.