What is Dentin?

You are not alone if you have ever experienced dental sensitivity. Nevertheless, not everyone knows dentin is responsible for tooth sensitivity and not enamel. Dentin is the tooth's intermediate layer (between the enamel and the pulp) and gives your teeth their color.



Dentin is denser and tougher than bone, contrary to the common belief that enamel is the most robust material in the body. The color of dentin can be of any shade ranging between grey, black, and even light yellow. And this yellow color is often seen through the enamel of teeth.

Composition of dentin

The dentin comprises around 45% mineral hydroxyapatite, 33% organic content, and 22% water by volume. It is one of the most fragile layers of teeth yet one of the least mineralized parts of the teeth. Therefore, it is equally delicate, and consequently, it executes the function of optimally keeping the enamel in its place. According to the Mohs scale, dentin has a mineral index of 3.

How is dentin different from enamel?

Two crucial elements of difference exist between the enamel and the dentin. The enamel has a duct shape that does not change throughout your life. But dentin gets its structure through the course of your life.

The other factor is sensitivity. The enamel is the hardest part of the oral cavity, and the entire body is the least sensitive. At the same time, dentin is more sensitive and fragile than enamel.


The process of formation of the dentin is called dentinogenesis. It starts before the enamel is formed, and the reason behind the process is the odontoblasts of the pulp. The extraction of dentin occurs from the dentin papilla of the tooth germs. The tooth germ is the fundamental structure through which every tooth develops. It includes the enamel organ, dental papilla, and dental sac surrounding them.


The dentin can be dyed and demineralized for histological examination. It is constituted of isotropic channels that are known as dentinal tubules. These tubules radiated outside the pulp to the enamel boundary or cementum on the exterior portion. The dentinal tubules connect the dentin enamel junction, or DEJ, across the crown and the dentinocemental intersection, or DCJ.

Types of dentin

There are three types of dentin: primary, secondary, and tertiary.

  1. The primary dentin is located between the enamel and the pulp chamber. It is the more visible type of dentin in the tooth.
  2. The secondary dentin develops after the completion of the root formation process, generally after the explosion of the tooth.
  3. The tertiary dentin is the type of dentin that is created from external stimuli, including cavities and wear.

However, broadly classifying a dentin mettle dentin can also be considered another type of dentin. It is the first type of dentin produced. The early dentin is more elastic than the other three types and offers a cushion to the enamel at the tooth crown.

What causes our tooth dentin to get exposed?

There are several reasons for it, which are as follows.

  • Tooth decay: The wearing down of the areas or holes in your teeth exposes your teeth to dentin
  • Gum diseases: Receding gums are a significant factor that causes exposing your dentin
  • Dental abrasion: Dental abrasion is a result of an excessively harsh brushing technique, which gradually causes your dentin to get exposed
  • Tooth whitening: The tooth whitening procedures cause your dentin layer to get exposed to bleaching agents, which thus causes your dentin to get eventually exposed.

How to take care of the dentin?

Dentin requires you to maintain good health, just like all other parts of teeth. The following methods can help you take care of your dentin ideally:

  • Gum grafting
  • Root canal treatment
  • Using pronamel toothpaste
  • Dental bonding
  • Treating underlying issues
  • Giving up smoking
  • Brushing your gums
  • Abiding triggering sensitivity
  • Using mouthwashes

Bottom Line

Dentin is crucial to our teeth anatomy as it carries out numerous vital functions. Therefore, taking care of your teeth is the most effective way to avoid issues impacting all of your teeth’ layers and surrounding oral tissue. Maintaining proper oral hygiene and having frequent exams to prevent any problems with your dentin is necessary.

If you feel you may have difficulties with dentin in a tooth or teeth, such as sensitivity or a recent injury to the mouth, it is worthwhile to schedule an examination at our well-equipped clinic. We can tackle a variety of difficulties with easy, safe solutions.

Dr. Michael

Dr. Michael

MSc Implantology, Bonn University, Germany