Final answer:
Dentin is the substance in teeth that continues to form throughout life and provides support to the enamel.
Step-by-step explanation:
The substance in the teeth that continues to form throughout life and supports the enamel is dentin. Dentin is a bone-like tissue that lies immediately beneath the enamel of the crown or the cementum of the root of a tooth. While both enamel and cementum are hard tissues that help protect the tooth, only dentin continues to grow and support the enamel throughout life.