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.
Dentin is the layer of the tooth just under the enamel. It is yellow in color. It is also softer that enamel. It is one of the three layers of the tooth. The enamel is the outer layer, the dentin is the middle layer, and the pulp is the inside layer. Decay that has extended to this layer of the tooth can spread rapidly, and needs to be treated quickly by a dentist.