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.
Parts of a Tooth. The part of the tooth that you can see is called the crown. The outer part of it is covered with a hard white material called enamel which protects the tooth. It is often hard and shiny and acts as a tooth's bodyguard. It protects the inside parts of the tooth.