Dentin

Dentin is the calcified layer of tooth structure that lies beneath the enamel on the crown and beneath the cementum on the root, forming the bulk of each tooth. It is made up of thousands of microscopic channels called dentinal tubules that connect to the nerve-rich pulp at the center of the tooth. Because dentin is more porous and softer than enamel, it wears more easily once the outer enamel is thinned or damaged. Exposed dentin is the primary cause of tooth sensitivity — when the tubules are open to the surface, hot, cold, sweet, or acidic stimuli travel directly to the pulp nerve. Dentin is naturally yellowish in color, which is why it shows through thinning enamel and affects the overall shade of the tooth even after whitening treatments. Protecting your enamel through good oral hygiene and avoiding acidic foods is the best defense against dentin exposure and sensitivity.