Question: there are 2 layers of dentine – what lies between
Answer: 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 .