Dentin is the creamy white to yellow mineralized substance which makes up the bulk of teeth, from the tusks of elephants to the incisors of canines. It is a dense matrix of minerals, primarily calcium, and it serves to protect the sensitive pulp of the tooth and create a base under the enamel, or outer coating of the tooth. Taking care of dentin is extremely important, because although it is dense and hard, it is susceptible to rot and infection, which can lead to oral pain and expensive dental treatments.

The formation of dentin starts with odontoblasts, cells which secrete collagen which forms into a dense matrix of tubes which grow out from the pulp of the tooth. These tubes are known as dentinal tubules, because they are the underlying structure of the dentin area of the tooth. As the tubes grow out towards the surface of the tooth, they become more widely spread apart, but the dentin is still fairly porous, thanks to the multitude of small holes in each tooth.

The majority of dentin is mineralized tissue. However, dentin also contains mineral rich fluids called dentinal fluids, which may be responsible for the mineralization of the dentin as it is secreted by the odontoblasts. Dentinal fluids contain proteins, sodium, and calcium, and are concentrated in the dentinal tubules.

Dentin is both harder and denser than bone, and for this reason has been a popular choice for carving and other traditional crafts. The dentin of elephants, commonly called ivory, has long been a highly prized commodity in many parts of the world, but other animals such as walruses and hippos have also been hunted for their dentin. Most craftspeople prefer to work with recently harvested dentin, which is more workable due to a higher moisture content. Individuals who own crafts made from dentin should keep them moisturized if they are not worn on the skin regularly to prevent them from cracking and losing their finish.

Caring for the living dentin in the mouth is an important part of routine dental care. If an infection manages to penetrate the much harder enamel of the tooth, it can quickly lead to rot of the dentin and pulp cavity. In addition to being uncomfortable, dental infections have been linked with other medical problems, such as septicemia. Make sure that all the animals in your life, including pets, receive regular dental care including checkups and cleaning, along with routine care like flossing, brushing, and the use of mouthwash.