Best dental clinic near me Why do I need a root canal? Your tooth consists of several layers. The outer layer is comprised of a hard, white enamel. Beneath your enamel is another hard layer called the dentin. And underneath the dentin is a soft tissue called pulp. Once your tooth’s pulp is damaged, it begins to break down. Bacteria will begin to grow and multiply within your tooth. It’s the growth of bacteria and other dying pulp remnants inside of your tooth that causes pain, irritation, infection, and worse. In this case, once root canal therapy is performed, your tooth can survive without the pulp because the tooth can be nourished by the surrounding tissues.