Tooth decay actually results when bacteria in your mouth feed on food debris and produce acid as a byproduct. Starchy,sweet and sticky foods are a primary culprit. This mix of food, acid, saliva and germs cling to your teeth as a filmy substance called plaque, which can erode tooth enamel and causes cavities to form. No matter what you eat, cavities will not form without the help of such bacteria. These germs can spread from mouth to mouth via shared food, utensils, kissing or even sneezing. Children are more susceptible of catching the bacteria from parents that have a history of decay because children have not built up their immunity yet. The bacteria is less likely to spread from adults because they have built up an immunity. Brushing morning and before bed as well as flossing will help fight tooth decay. Regular cleanings, recommended every six months, can help prevent decay and reduce the levels of cavity causing bacteria in your mouth.