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 basic structure of a tooth consists of three main regions: 1  enamel - the surface layer of the tooth that is hard and protective. 2  dentine - makes up the bulk of the tooth. 3  pulp cavity - contains the blood vessels and nerves that feed and innervate the tooth.