Re: What is the exact composite of tooth?

Teeth are actually made up of three different hard tissues surrounding a pulp chamber. The pulp chamber located in the center of the tooth contains connective tissue, blood vessels, nerves, lymphatic vessels, and just about everything else you would find in connective tissue throughout the body. The primary function of the pulp is to supply nutrients for odontoblasts, which are the cells that produce dentin. The dentin layer is the next layer from the center towards the outside of the tooth. It completely surrounds the pulp chamber. Dentin is just a little bit harder than bone due to its high mineral content. Dentin is 70% inorganic, the inorganic component is primarily hydroxyapatite crystals which are made mostly of calcium and phosphate. The remainder of dentin is made up of 20% collagen type I (which is a protein common to connective tissue) and 10% water.

The second hard tissue component of a tooth is enamel. Enamel covers only the crown portion of the tooth. This is the part of the tooth that can be seen when looking in someones mouth. Enamel covers the dentin on this part of the tooth and is typically 1.5 to 2 mm thick. Enamel is the hardest tissue in the body. It is made up of 96% mineral (hydroxyapatite) and only 4% inorganic and water. There is no collagen in enamel.

The third hard tissue component of a tooth is cementum. Cementum covers the root of the tooth. It lies over the dentin in this portion of the tooth and is typically 1 mm thick. The composition of cementum is very close to that of bone, it is 65% mineral (hydroxyapatite), 23% organic (mainly collagen type I) and 12% water.

I hope that the above description of tooth composition is exact enough for your purposes. If you want to know more about hydroxyapatite most chemistry books have a section on the effect of fluoride on hydroxyapatite crystal formation (fluoride can react with hydroxyapatite to make a more stable and harder crystal, which means stronger enamel that is more resistant to tooth decay); and if you want to know more about the structure of collagen most histology or anatomy books have some information about its formation. Good luck in your studies.