Unlike what the public think, pain is not the first sign of a cavity. A cavity will start as a white area that you cannot brush away which is called a white spot. The enamel of the white spot will start to deteriorate – or decalcify- under the acid attack produced by the bacteria. During the initial stages of decalcification, we can reverse the process by using certain tooth pastes such as MI paste. This tooth paste has a unique ability to release calcium and phosphate back to tooth surfaces.