HOW DOES A TOOTH BECOME INFECTED?
In order to understand how your tooth became infected, let’s first take a look at the structure of a tooth. Every tooth in your mouth is covered with two protective layers. The outer most layer is enamel, which is the hardest substance in the human body. Underneath that is dentin, a slightly softer material that transmits sensations such as hot and cold temperatures to the nerve deep inside a tooth.
Although both enamel and dentin are quite hard, they are susceptible to the acids produced by oral bacteria. These acids can begin to erode the enamel and cause a cavity. If not treated, the cavity can enlarge and give bacteria access to the innermost portion of the tooth called the pulp chamber. Similarly, a penetrating crack or serious fracture may also expose the chamber.