There four major tissues which compose the tooth: enamel, dentin, cementum and pulp. Dental enamel is the hardest tissue not only in the tooth but also in the whole human body. Like any part of organism tooth enamel contains water and organic component but only 4% in total and other 96% go to the mineral compounds. The natural color of tooth enamel can be different: from light yellow to grayish white. But a teeth color in general depends not only on enamel color because the enamel is semitransparent. That is why underlying dentin has a great influence on the appearance of a tooth. Also certain elements of everyday life like coffee, tea, tobacco as well as bacteria stains are able to provoke a discoloration of tooth enamel. The main mineral of enamel is a calcium phosphate.
Dentin is situated between the tooth enamel and the pulp. It is also a protective layer but softer than dental enamel and composed of 70% organic substance advantageously of collagen proteins. The material of dentin is yellowish and porous.
Pulp makes part of a tooth which corresponds to so-called "dental nerve" and accounts for the tooth sensibility. There are located nerves and blood vessels.
Cementum protects the teeth roots. This is a bony substance produced by the cells of the tooth root. Cementum is softer than dental enamel and dentin.
Forward Contract
ReplyDeleteForward contracts are the oldest and the simplest form of derivative contracts. A forward contract is an
agreement between two persons for the purchase and sale of a commodity or financial asset at a specified
price to be delivered at a specified future date.
porusmistry