About Enamel

Tooth enamel is the substance that makes up the outer layer of human teeth, as well as the teeth of all vertebrate mammals. Enamel is 96 percent minerals, with water and organic material composing the rest. It is the hardest tissue in the human body, and as a result, humans rely heavily on enamel to effectively chew and grind food, as well as protect the rest of the tooth from physical and chemical decay.

Structure

• The main chemical in enamel is a calcium phosphate [Ca3(PO4)2] mineral called hydroxylapatite. It is structured as millions of tiny units called "enamel rods," which are packed parallel together in long strands and connected to the underlying dentin layer of the tooth. Enamel is typically grayish-white in color, and is semi-translucent. The yellow color of the dentin layer, combined with enamel's translucency, is the most common reason why unhealthy teeth appear yellow in pigment.

Formation

• The formation of enamel is a two-stage process called "amelogenesis." The initial "secretory" stage occurs after the formation of the dentin layer of the tooth, when cells called "ameloblasts," unique to tooth development, are formed. The ameloblasts secrete the essential proteins and enzymes of enamel and form the layer's basic structure. The final "maturation" stage involves the secretion of the remaining substances essential to enamel formation, and completes the rigid, mineralized structure of the outer layer of the tooth.

Tooth Decay

• Due to enamel's mostly-mineral structure, it is vulnerable to demineralization which leads to decay of the enamel layer, resulting in cavities. Erosion of enamel is the most common problem in oral hygiene. It is most commonly caused by excessive ingestion of sugars and sucrose, most commonly found in candy, soft drinks, and fruit juices. Since enamel is not made up of living tissue, it cannot repair itself, and requires special dental procedures to fill cavities. Tooth decay can also be caused by acid reflux disease, grinding of teeth, and excessive vomiting due to diseases such as alcoholism and bulimia.

Oral Hygiene

• Though enamel decay is easily brought about by frequent sugar intake, it is also easily prevented through good oral hygiene practices. Humans generally need to brush their teeth twice a day to prevent the buildup of dental plaque, which releases harmful bacteria that contribute to the erosion of enamel and creation of cavities. Flossing is also an important dental procedure, as it removes plaque and tiny bits of food stuck between the teeth that can quickly and clandestinely decay the enamel.

Beneficial Foods and Drinks

• Despite the presence of many sugar-heavy foods and drinks that are detrimental to enamel, there are also several foods and drinks that provide positive health benefits to it. Food from animals, such as beef, eggs and poultry, contains high levels of phosphorus, which helps strengthen the calcium found in enamel. Cheese is a food rich in calcium and phosphate, and the high vitamin A content of vegetables such as carrots and broccoli accelerates enamel development. Green tea is a popular drink for healthy teeth, as it contains polyphenols, antioxidants that reduce plaque's adherence to the teeth and gums.