Which tooth structure is approximately 70% inorganic materials and contains tubules?

Dentin is the tooth structure that is approximately 70% inorganic materials, primarily hydroxyapatite, and contains microscopic tubules. These tubules house the projections of odontoblasts, which are cells responsible for dentin formation and the maintenance of its vitality. The presence of these tubules plays a crucial role in the sensitivity of teeth, as they allow for the transmission of sensations, such as temperature and pressure, to the pulp tissue.

In contrast, enamel, while also largely inorganic, is about 96% mineral, making it the hardest substance in the body, but it does not contain tubules. Cementum, which covers the roots of teeth, has a lower percentage of inorganic material, consisting of approximately 50-60% of its composition. Pulp is made up primarily of soft tissue, including nerves and blood vessels, and contains no inorganic materials; it is essential for nourishment and sensory functions. Understanding these differences is key in recognizing the roles and characteristics of various dental tissues.