As anticipated and as can be seen in the figure, the enamel covers the crown like a cap, reaching its maximum thickness in the chewing surface (cusp) and tapering near the collar, where it is in turn covered with cement.
Despite its hardness, enamel - which has no cells or blood vessels inside it (avascular tissue) - appears highly fragile. This fragility becomes evident when the underlying, porous elastic tissue called dentin is missing. Furthermore, the enamel, although in different percentages in the various areas of the crown, is very sensitive to acids, so it can be affected by the oral bacteria responsible for caries.
Enamel, also known as adamantine substance, is made up of elongated polyhedral prisms, held together by a special highly mineralized interplasmic substance. These prisms represent the fundamental unit of the enamel: rod-shaped, then elongated and arranged parallel to each other, they have a diameter of about 3-10 micrometers and run from the deep surface (amelo-dentinal junction) to the outer surface of the enamel. Deeply, the prisms are perpendicular to the dentin, then become wavy in the central section and finally perpendicular to the tooth surface.
, tea, chewing tobacco, cigarettes, betel nuts and more. The chromatic alterations of the tooth can also be caused by diseases (fluorosis) or by taking particular drugs, such as high-dose tetracycline, especially if taken by the mother during neonatal life.(for the acid attack of self-induced vomiting);
On the advice of the doctor or dentist, fluoride can be a good aid to re-mineralize the enamel and prevent its erosion; however, it is important not to overdo it: the excess of fluoride can cause adverse effects to those desired, seriously damaging the tooth. To learn more, see the article: fluoride toothpaste.
