Wat is tooth decay?? help us were doing a science project and we need more info?

I am a dentist. To answer this question the proper name for tooth decay should be used. Search on the internet for "dental caries" which is = tooth decay. Dental caries is the actual dissolving away of tooth structure by trying to maintain a pH equilibrium in the mouth. The process is actual quite complex and don't quote me exactly on this. When you eat something, chew gum, have something in your mouth your body reacts by lowering the pH of the mouth to a more acidic environment for 30 minutes. This is done to help start to digest and break up food in the mouth and swallow more easily as a bolus. There are hundreds of types of bacteria in the mouth and two are most often noted as contributing to dental caries; mutans streptococci and lacto bacilli. When you eat sugary foods these bacteria attach to the tooth surface and feed off the sugar. The by-products (waste) of these bacteria is acidic dental plaque, the white sticky stuff on teeth after you eat or drink something sugary. If the plaque doesn't get brushed off then it can harden and turn into calculus causing gum tissue problems. As they continue to feed off the sugars in your mouth the acidic plaque stays right on the tooth surface. Everything in this world is in equilibrium with something, so likewise the more acid created by the bacteria the lower the pH of the tooth and mouth gets, the tooth actually begins to dissolve in equilibrium to try to buffer the low pH. This dissolving is where the decay is. I may not be completely right in every part there but that is the main way teeth decay.