Tooth decay is a condition that indicates damaged tooth enamel, aka a hard outer layer of teeth. This condition can be a problem in children, adolescents, and adults. The layer of bacteria attached to the tooth, or so-called plaque, will continue to form on your teeth. When you eat or drink something that contains sugar, the bacteria in the plaque will produce an acid that attacks the enamel. The sticking of plaque will keep the acid in contact with your teeth, and at any time the enamel will rupture to produce a hole in the tooth.
Case cavities are more commonly known among children, but changes in teeth that occur due to aging can make cavities also become an adult problem.