The enamel is the visible surface of the tooth, which is supported by dentin from the inner part of the tooth. 96% of the enamel is mineral substances, the leftover is water and organic substances. Because the enamel is transparent, the colour of the dentin highly influences the colour of the enamel. The colour of the enamel can range from bright yellow to greyish white.
Its thickness differs depending on the surface of the tooth. Usually the enamel is the thickest on the cuspal part of the tooth and it gets thinner towards the gums till it reaches the point where the enamel and the cementum meet.
Caries are caused by the bacteria living in our mouth and producing acid from the meals we eat. The acid attacks the enamel and causes the loss of important mineral substances. The mineral substances lost in the attack of the acid can be substituted with the substances carried by the saliva, and fluoride also helps strengthening the enamel.
Unfortunately due to caries you may need tooth filling as well.