The major component of the dentin organic matrix is collagen.

• A. True
• B. False
• C. Not sure
• D. Not applicable

Answer: (A)

Collagen type I forms the major portion of the dentin organic matrix. Odontoblasts secrete an extracellular matrix rich in type I collagen, creating a fibrous scaffold that guides mineral deposition. The mineral phase, hydroxyapatite, is laid down along and within this collagen network, so the collagen scaffold largely determines the organic component and the mechanical properties of dentin. Non-collagenous proteins and proteoglycans are present but in smaller amounts and mainly modulate mineralization rather than replace collagen as the primary component. Overall, dentin’s organic matrix is dominated by collagen, with other organic molecules playing supportive roles, so the statement is true.