<P> Dentin ( / ˈdɛntɪn / ) ( American English ) or dentine ( / ˈdɛnˌtiːn / or / ˌdɛnˈtiːn / ) ( British English ) ( Latin : substantia eburnea ) is a calcified tissue of the body and , along with enamel , cementum , and pulp , is one of the four major components of teeth . It is usually covered by enamel on the crown and cementum on the root and surrounds the entire pulp . By volume , 45 % of dentin consists of the mineral hydroxylapatite , 33 % is organic material , and 22 % is water . Yellow in appearance , it greatly affects the color of a tooth due to the translucency of enamel . Dentin , which is less mineralized and less brittle than enamel , is necessary for the support of enamel . Dentin rates approximately 3 on the Mohs scale of mineral hardness . There are two main characteristics which distinguish dentine from enamel ; firstly dentine forms throughout life , and secondly , dentine is sensitive . </P>
<P> Dentin ( / ˈdɛntɪn / ) ( American English ) or dentine ( / ˈdɛnˌtiːn / or / ˌdɛnˈtiːn / ) ( British English ) ( Latin : substantia eburnea ) is a calcified tissue of the body and , along with enamel , cementum , and pulp , is one of the four major components of teeth . It is usually covered by enamel on the crown and cementum on the root and surrounds the entire pulp . By volume , 45 % of dentin consists of the mineral hydroxylapatite , 33 % is organic material , and 22 % is water . Yellow in appearance , it greatly affects the color of a tooth due to the translucency of enamel . Dentin , which is less mineralized and less brittle than enamel , is necessary for the support of enamel . Dentin rates approximately 3 on the Mohs scale of mineral hardness . There are two main characteristics which distinguish dentine from enamel ; firstly dentine forms throughout life , and secondly , dentine is sensitive . </P>
there are 2 layers of dentine -- what lies between
there are 2 layers of dentine -- what lies between
pulp
pulp