- The enamel of the teeth: protection, this Nature
The structure of tooth enamel
The enamel covering the crown of the tooth, is the hardest of his cloth. Most hard enamel layer (1, 6-1, 7 mm) is on the chewing surface of the small and large molars. On the lateral surfaces of the tooth crown ply thereof is considerably thinner. Enamel hardness is less than five times the hardness of quartz.
Enamel is composed of enamel prisms diameter of 3-6 microns that pass through the full thickness. Part of the enamel prisms, tapering gradually disappears. Not reaching the surface of the enamel. Some prisms divided into two, and the compound is sometimes observed in one of the two prisms. In its course of enamel prisms form s-bends, so the longitudinal section (section) of the tooth enamel prisms some parts are cut longitudinally and transversely others. The alternation of longitudinally and transversely of grinding parts of enamel prisms creates the effect of the appearance of light and dark bands (bands Gunter-Shregera). In thin sections of enamel still visible lines running in an oblique direction - the so-called line of Retzius - their appearance is associated with more or less salt content of lime, different refracting light.
Violation of enamel formation can occur as a result of past diseases or malnutrition in early childhood. For example, thin sections of teeth is noticeable so-called neonatal line in the form of a dark band in the enamel of primary teeth
Milk teeth - how they are formed?
. This band is like a boundary between the enamel formed before birth and after birth. The origin of this line to explain a violation of enamel calcification during the adaptation of a newborn baby to a new kind of food after birth.
In themselves enamel prisms has transverse striations, which is a reflection of the daily rhythm of salt deposits
The deposition of salts - a disease of old men?
The enamel contains a large amount of mineral salts (96-97%), organic matter is 3-4%. Electron microscopic studies revealed that the structural unit of enamel prisms - salt crystals (gidooksiapatita) tight to each other. Inside the fan-shaped prisms are arranged, i.e. lie at an angle to each other, this angle being open towards the surface of the enamel. Between the enamel prisms are joined using mezhprizmennogo substances and penetration crystal prisms in some other neighbor.
Mezhprizmennoe enamel material formed consists of crystals of the same gidrooksiapatita as prisms themselves, but different crystal directions. Number mezhprizmennogo matter differently, sometimes do not, and prisms in contact directly.
Biohimchesky enamel composition - this is mainly the apatite crystals (about 98% - hydroxyapatite, carbonate-apatite, fluorapatite) and only 2% neapatitnyh crystals (Octacalcium phosphate, dicalcium phosphate and calcium phosphate). Hydroxyapatites very sensitive to acids, so the destruction of enamel begins with a slight increase in acidity.
The enamel contains traces of sodium, magnesium, zinc, potassium, lead, strontium, iron, fluoride ion and other small components. In addition, it contains a small amount of proteins, fats and carbohydrates. Water with enamel around 4%.
The enamel contains no blood vessels and nerves, its food and transport of various substances is based on the physiological mechanisms: permeability, circulation of liquid enamel, solubility, and ion exchange.
Solubility and remineralization of enamel - two dynamic processes (dissolution of crystals gidrokiapatita and re-education), which provide updates and persistence component enamel. Exchange of mineral elements is performed at an ion exchange involving catalysts (accelerators biochemical reactions) that are micronutrients.
How to save the tooth enamel
The enamel of teeth is well maintained in an alkaline environment - that such an environment is normally in the mouth. But in various diseases of the oral cavity multiply pathogens that produce enzymes and other waste products, souring environment that contributes to the destruction of enamel. In addition, if you do not rinse your mouth after each meal, in the teeth become stuck leftovers, by the decomposition of which also produce acids that destroy tooth enamel. Therefore of paramount importance oral hygiene
Oral hygiene - not only in the dentist's chair
, Which includes tooth cleaning twice a day, and rinsing the mouth after each meal.
Enamel - is the protection that is given to our teeth to protect them from destruction.