Sources: American Heart Association. Heart Disease and Stroke Statistics - 2009 Update; CDC, Heart Disease and Stroke Prevention Addressing the Nation's Leading Killers, At A Glance, 2011. Heart disease and stroke are the first and fourth leading causes of death in the United States.
Your teeth are composed of four dental tissues. Three of themâenamel, dentin and cementumâare hard tissues. The fourth tissueâpulp, or the center of the tooth that contains nerves, blood vessels and connective tissueâis a soft, or non-calcified, tissue.
The Parts of the Tooth. A tooth is divided into two basic parts: the crown, which is the visible, white part of the tooth, and the root, which you canât see. The root extends below the gum line and anchors the tooth into the bone. Your teeth contain four kinds of tissue and each does a different job.