The primary inorganic component of dentin is calcium hydroxyapatite, Ca10(PO4)6(OH)2.
Dentin, the tissue that forms the bulk of a tooth, is a composite material composed of both organic and inorganic components. Its composition, by weight, is approximately:
- 70% inorganic material
- 20% organic material
- 10% water
The inorganic portion provides dentin with its rigidity and hardness. While calcium hydroxyapatite is the predominant inorganic component, other elements are also present in smaller quantities. These can include:
- Calcium: A key component of hydroxyapatite.
- Phosphate: Also a key component of hydroxyapatite.
- Carbonate: Can substitute for phosphate within the hydroxyapatite crystal structure.
- Fluoride: Can substitute for hydroxyl ions in hydroxyapatite, forming fluorapatite, which is more resistant to acid dissolution (and therefore dental caries).
- Trace elements: Minor amounts of other elements may be incorporated into the mineral structure.
The specific composition of the inorganic phase can vary depending on factors such as age, diet, and exposure to fluoride. The well-organized arrangement of these mineral crystals within the dentin matrix contributes significantly to the overall strength and resilience of the tooth.
