What Is the Dentin, What Function Does It Serve, And How Can You Protect It?

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What is the dentin, what function does it serve in the context of your oral health, and how can you best take care of it to keep it strong and healthy?

The dentin, or dentine as it is also called, is a vital but often overlooked part of the overall tooth structure. As long as the tooth’s enamel remains intact, the dentin exists as a thin, hidden layer of material directly underneath the tooth’s enamel where it forms a protective covering over the dental pulp chamber. The dentin varies in thickness and texture depending on where on the tooth it is.

The dentin’s primary purpose and function within the body is that of protecting the dental pulp chamber against bacteria and infection. When a tooth’s enamel erodes, the first thing that happens is dentin exposure. Although the dentin is stronger and more resilient than the pulp itself and is able to keep harmful bacteria at bay for a short while, it is important to understand that it is very vulnerable to breaking down once exposed.

Once bacteria gets inside the pulp chamber, the only solution is a root canal treatment where your dentist removes all of the pulp and nerves from your tooth cavity before replacing it with a filling and potentially a crown.

All in all, it is much easier, more pleasant, and decidedly less expensive, to avoid dentin exposure and tooth infection in the first place.

In this article, we’ll walk you through each dentin layer, talk about what happens if the dentin becomes exposed or infected, and give you the keys you need to be able to keep your teeth intact and your dentin covered. Without further ado, let’s get to it.

The anatomy of teeth

The anatomy of a tooth consists of four major components. These are, in order of appearance, the outer hard enamel, the dentin layers, the pulp chamber, and finally the dental cementum.

Outer hard enamel

As you are probably already aware, the outermost layer of the tooth is called the enamel.

The enamel is the hardest part of the tooth – it is tough, hard-wearing and un-elastic. Its function is to enable you to chew, as well as to protect the tooth’s vulnerable insides against infection and decay.

Primary dentin layer

The dentin itself is a rigid yet somewhat elastic layer that exists directly underneath the enamel, undergirding and supporting it. Dentin has the advance of being less brittle and therefore less breakable than the enamel.

The dentin is the go-between between the tooth’s hard enamel and soft pulp. It not only protects the pulp, it also absorbs any shocks and impacts that result from chewing and biting down hard. Without your dentin, your teeth would break in no time. There would also be nothing to protect your pulp chambers from exposure to harmful bacteria when the enamel sometimes wears down or breaks down.

As well as protecting your pulp chambers and supporting your enamel, your dentin is also responsible for transmitting impulses from the teeth roots or enamel. These impulses could include pressure and temperature.

The dentin itself is multi-layered. Primary dentin formation takes place before tooth eruption, while secondary and teritary dentine layers develop after the eruption and develop further as you age.

The primary dentin layer is the outermost layer of dentin which is in constant and direct contact with the enamel. 

Secondary dentin layer

The secondary dentin layer is the name given to the part of the dentin that is contact with the teeth’s cementum at the base of the tooth. It forms only after tooth eruption, and is quite thick.

Tertiary dentin layer, or reparative dentin

Teritary dentin only forms in response to tooth decay, excessive tooth grinding and other negative stimuli.

In other words, your body produces tertiary dentin only when it is provoked to do so. As such, tertiary dentin is part f the tooth’s natural defensive mechanism and helps it protect itself against infections and abscesses. 

Because of its protective and reparative qualities, teritary dentin is also often referred to as reparative dentin. 

Dental pulp

Your dental pulp or dental pulp chamber is the soft innards of your teeth. They consist of blood vessels and nerve bundles, and as you can either imagine or have experienced first-hand, the pulp chambers are very sensitive and vulnerable if they become exposed. 

Both the dentin and the outer enamel serve to protect the dental pulp, and for the most part, they do so very successfully. It is only if your tooth cracks or breaks, or if your enamel becomes eroded over time, that you will experienced dentin exposure and eventually tooth decay.

Dental cementum

Dental cementum is a form of living tissue that continues to grow and develop throughout your entire life. In short, dental cementum is a calcified material that covers and protects the outside of your tooth root.

The dental cementum is vitally important, as it provides the attachment point for your gums to hold your teeth within their sockets in the jaw bone.

Dentin structure

The dentin is best described as an organic matrix.

Dentin is a complex and unique structure both functionally and physically. It is multi-layered and varies in thickness and makeup depending on where on the tooth it is. For example, the dentin found underneath the crown of the tooth, which is called mantle dentin, is especially resilient and able to withstand pressure from chewing and biting that would otherwise cause the tooth enamel to fracture.

By contrast, the circumpulpal dentin forms the largest part of the dentin layer and surrounds the pulp cavity. It is much thinner and less resilient than mantle dentin, as it isn’t built to be able to withstand as much force.

Dentin is filled with tiny, s-shaped tunnels. These tunnels are what give dentin its elasticity and permeability.

Dentin appearance

The color or dentin can vary significantly and ranges from nearly black to pale yellow. This explains why, when a tooth’s enamel becomes worn or eroded, you will start noticing brown spots on the tooth in question. What you are really seeing is dentin exposure as the protective layer of enamel is broken down by bacteria. 

Dentin exposure

If the outer enamel of your tooth cracks or break, you will be able to see the dentin underneath. This is called dentin exposure.

When dentin exposure occurs, your tooth will produce tertiary dentin in an attempt to protect itself against incoming infection and the potential formation of abscesses. 

Exposed dentin should never be left untreated. Unlike the much harder and stronger enamel, the dentin is not built to withstand decay and bacteria for long. If your dentin becomes exposed, no matter what the reason is, you should see your dentist as soon as possible to get the tooth repaired. 

If your dentin becomes exposed due to a tooth breaking, you’ll notice right away. But when dentin exposure can also happen more slowly and gradually as a result of enamel erosion. When this happens, the symptoms to watch out for are hypersensitivity and pain when your teeth come into contact with hot or cold temperatures, or with foods that are either very spicy, acidic or sweet.

How to care for your dentin

Caring for your overall oral health and hygiene is synonymous with caring for your dentin. Another way of putting it would be to say that if you take great care of your teeth’s enamel, the dentin substrate will take care of itself. 

The goal here is to protect the enamel so that it doesn’t wear away to expose the dentin. 

Of course you cannot fully guard yourself against the unexpected, and so it is always possible for the dentin to become exposed as a result of an accident or simply biting down too hard. That are side, here are the daily initiatives you can take to protect your teeth from dentin exposure and decay.

Oral hygiene

Gentle brushing twice a day is the cornerstone of great oral health. Ideally you should brush once in the morning and once in the evening just before going to bed. 

Coming from a place of wanting to take the best care of your teeth that you possibly can, it can be tempting to brush more than the recommend two times a day. There are, however, plenty of good reasons why you shouldn’t, and why brushing too frequently can have the opposite effect to what you intend.

If you are currently using a hard-bristled brush, switching to one with softer bristles can prove pivotal. Hard-bristled brushes offer the short-term advantage of a very thorough clean, but over time the tougher bristles can really wear down your enamel to expose the dentin underneath and leave your teeth more vulnerable. 


Minding your diet also plays an important role in taking excellent care of your teeth. Eating a balanced diet that is rich in minerals and vitamins is the way to go if you want to main both strong gums and healthy teeth.

A balanced diet includes plenty of fruit and vegetables, as well as whole grains and legumes. You may also want to add supplements to ensure your body is getting all of the different nutrients it needs in abundance.

By the same token, you should avoid sugary and highly acidic foods as much as you can. Sugary and acidic foods can taste wonderful, but they are extremely bad for your enamel. Sugary and acidic foods and drinks are particularly dexterous when it comes to causing bacteria-filled plaque to form and eroding your enamel.


You cannot safeguard your teeth against any eventuality, but there are still obvious pitfalls you can easily avoid.

If you play contact sports of any kind, make sure you are always wearing a protective mouthguard when you are on the field or in the ring. A mouthguard can be the difference between losing a tooth – or risking exposed dentin – and keeping all of your teeth intact.

Likewise, if you are grinding your teeth at night (This is a surprisingly common issue also known as nighttime bruxism), you should wear a mouthguard to bed to protect your teeth against cracking or breaking under the force of your tooth grinding

Frequently asked questions

What is the function of the dentin?

Dentin serves to primary functions. One is to absorb the pressure and impact from biting and chewing. Because the dentin is softer than the enamel and has elastic properties it is able to keep the enamel from breaking when you bite down hard or use your teeth to chew something tough or sinewy.

Dentin also forms a protective covering over the dental pulp, which is soft and full of nerves. If your enamel breaks, your dentin may still be able to keep the pulp intact.
However, dentin cannot keep bacteria at bay for long and will break if not covered up by a dentist as soon as possible after becoming exposed.

What is the dentin on your teeth?

The dentin is a layer of elastic, protective material that separates your teeth’s pulp chambers from the outer layer of enamel. As long as your teeth are intact, you won’t ever see the dentin as it is fully covered and protected by your enamel.

Where is dentine?

The dentine, or dentin as it is just as frequently called, is inside each tooth, directly underneath the tooth enamel.

What is tooth dentin made of?

There are multiple different types of dentin, and they all have somewhat different structures. The simple answer would be that dentin is a hard, calcified tissue. In many ways, dentin is similar to bone in that it is hard yet flexible.

Dentin formation includes the formation of microscopic S-shaped tunnels within the dentin structure, which gives dentin a small degree of elasticity and permeability. It is also via these s-shaped tunnels that sensations are transmitted throughout the tooth. In other words, dentin is what allows your teeth to sense temperature changes in food and drinks.

Dr Febin Mary George - Editor

With more than 10 years as a dental surgeon, Dr Febin Mary George is passionate about educating consumers around the world to help look after their teeth.

She completed her Bachelor of Surgery at the Century Institute of Dental Science and Research Centre in 2010.

Alongside editing the International Journal of Dental Clinics she has also written for major publications including Thrive Global.