Humans usually have 20 primary (deciduous or “baby”) teeth and 32 permanent (adult) teeth. Teeth are classified as incisors, canines, premolars, and molars. Incisors are primarily used for biting pieces from foods such as raw carrots or apples and peeled but uncut bananas, while molars are used primarily for grinding foods after they are already in bite size pieces inside the mouth. (Source: http://en.wikipedia.org/wiki/Tooth_(human)) The Canines are used for tearing food.
Teeth are made up of the following parts:
- Enamel – Enamel is the hard white substance that crowns the tooth and forms a protective covering over the tooth. It is the only visible part of the tooth that’s above the gums. According to wikipedia.org, 96% of enamel consists of mineral, with water and organic material comprising the rest. The normal color of enamel varies from light yellow to grayish white. At the edges of teeth where there is no dentin underlying the enamel, the color sometimes has a slightly blue tone. Enamel’s primary mineral is hydroxylapatite, which is a crystalline calcium phosphate. The large amount of minerals in enamel accounts not only for its strength but also for its brittleness. (Source: http://en.wikipedia.org/wiki/Tooth_(human))
- Dentine – Dentin is the bone-like layer (softer than enamel) that lies between the enamel or cementum and the pulp chamber. Dentine surrounds and protects the pulp chamber and also supports the crown to help teeth keep their shape. It is said that dentine can heal itself, hence it is the beginning stages to remineralize teeth.
- Pulp – Pulp is the softest, deepest part of the tooth filled with soft connective tissue. It contains nerves and blood vessels that bring nutrients to the tooth and also transmit signals like hot, cold, or pain between the brain and the soft center of the tooth.
- Cementum – Cementum is a layer of hard, bone-like tissue that covers the pulp and the root of the tooth. Its yellowish in color and it is softer than either dentin or enamel. It helps to hold the tooth in the socket by giving the periodontal ligament a way to attach itself to the tooth for stability.
- Crown – This is the visible part of a tooth that’s above the gums.
- Root – Root is the part that is hidden from sight as it lies below the gum line, where the tooth is anchored into the jawbone.