What is the thickest layer in a tooth?

The thickest layer in a tooth is dentin. Dentin is a calcified tissue that provides the majority of a tooth's structure and lies directly beneath the enamel and cementum, surrounding the pulp. It is significantly thicker than both enamel, which is the hard outer layer that protects the tooth, and cementum, which covers the roots of the teeth and helps to anchor them in the jawbone. While pulpal tissue is essential for tooth vitality, it does not contribute to the overall thickness of the tooth structure in the same way that dentin does. Dentin's role is crucial, as it also contains microscopic tubules that allow for communication with the pulp, contributing to the tooth's response to stimuli.