Can You Fix Tooth Dentin?

Dentine cannot completely grow back once a physical piece of tooth structure has been lost. However, dentine is part of a biologically active pulp-dentine complex and can respond to irritation in several ways. A vital tooth can lay down new dentine internally, some demineralised dentine can potentially remineralise, and dental treatment can protect or replace structure that has been lost.

In the UK, the tissue is normally called dentine, while dentin is the more common American spelling. Both words describe the same tissue.

Can Dentine Grow Back?

The answer depends on what is meant by “grow back”. If a cavity, fracture or tooth wear has physically removed a section of dentine, the tooth cannot recreate the original shape of that missing area by itself.

However, a living dental pulp can respond to injury by producing tertiary dentine on the inside of the tooth, between the injury and the pulp. This is a defence mechanism designed to protect the pulp rather than rebuild the missing outside surface.

Dentine therefore has a greater biological repair capacity than enamel, but this should not be confused with complete regeneration of a damaged tooth.

What Is Dentine?

Dentine is the mineralised tissue that forms most of the structure of every tooth. In the crown it lies underneath enamel, while around the root it is normally covered by cementum.

At the centre of the tooth is the dental pulp, which contains blood vessels, nerves, connective tissue and the cells responsible for producing dentine.

Dentine therefore sits between the hard outer tissues of the tooth and the living pulp inside.

What Is Dentine Made Of?

By weight, mature dentine is approximately:

• 70% mineral, principally hydroxyapatite
• 20% organic material, predominantly type I collagen
• 10% water

This makes dentine considerably less mineralised than enamel. Its collagen-rich structure also makes it less brittle and helps support the enamel above it.

Is Dentine a Living Tissue?

Dentine itself does not contain blood vessels and mature dentine does not contain cells throughout its mineralised matrix in the same way as bone.

However, dentine is intimately connected to the living dental pulp. Cells called odontoblasts line the outer edge of the pulp and extend processes into microscopic channels within the dentine.

For this reason, dentists commonly consider dentine and pulp together as the pulp-dentine complex. This living system can respond to decay, wear, trauma and restorative treatment.

What Are Dentinal Tubules?

Dentine contains thousands of microscopic channels known as dentinal tubules. They run from the pulp towards the outer surface of the dentine.

The tubules contain fluid and are closely associated with odontoblast processes and the underlying pulpal tissues.

The number and diameter of dentinal tubules increase as they approach the pulp. This is one reason deeper dentine behaves differently from dentine closer to the outside of the tooth.

Why Does Exposed Dentine Hurt?

When enamel is lost or a tooth root becomes exposed, dentinal tubules can become open to the oral environment.

The most widely accepted explanation for dentine hypersensitivity is the hydrodynamic theory. Cold air, drinks, touch, sweet or acidic substances can cause rapid movement of fluid within open dentinal tubules. This movement stimulates sensory structures associated with the pulp and can produce a short, sharp pain.

Not every area of exposed dentine is sensitive. Hypersensitive surfaces tend to have a greater number of open tubules and more rapid fluid movement.

If you have persistent sensitivity, a dental examination is important because decay, cracked teeth, defective fillings and pulpal problems can produce similar symptoms.

What Are the Different Types of Dentine?

Primary Dentine

Primary dentine forms during tooth development and makes up the majority of the dentine in a mature tooth.

Secondary Dentine

Secondary dentine forms slowly after the tooth has developed and continues to be deposited throughout life.

Because it forms on the pulpal surface, the pulp chamber and root canals can gradually become narrower as a person gets older.

Tertiary Dentine

Tertiary dentine develops locally in response to irritation or injury, such as tooth decay, wear or trauma.

There are two important forms of tertiary dentine.

Reactionary Dentine

If an injury is relatively mild and the original odontoblasts survive, these cells can increase their activity and produce reactionary dentine.

This creates additional mineralised tissue between the source of irritation and the dental pulp.

Reparative Dentine

If an injury is severe enough to destroy the original odontoblasts, cells within the pulp can sometimes differentiate into new odontoblast-like cells.

These cells may produce reparative dentine. This tissue tends to be less regularly organised than normal primary dentine but can form part of the tooth’s biological defence against injury.

Does Tertiary Dentine Replace a Cavity?

No. Tertiary dentine forms internally, towards the pulp. It does not normally fill the external hole created by a cavity.

For example, if tooth decay has created a substantial physical cavity, the tooth may still require a dental filling even if tertiary dentine has formed underneath the lesion.

The biological response and the dental restoration serve different purposes: the tooth attempts to protect its pulp internally, while the dentist restores the lost external tooth structure and creates a seal against the oral environment.

Can Demineralised Dentine Remineralise?

There is an important difference between demineralised dentine and physically missing dentine.

Dentine that has lost some mineral but retains enough of its collagen framework may potentially undergo some remineralisation when the disease process is controlled and suitable minerals are available.

This is very different from growing an entirely new section of tooth where dentine has already been destroyed or removed.

Modern dentistry therefore aims to preserve healthy and potentially recoverable tooth structure wherever this can be done safely.

Does a Dentist Have to Remove All Decayed Dentine?

Not necessarily. Older approaches often focused on removing all softened or discoloured dentine until only hard tissue remained.

Modern evidence supports a more conservative approach in many moderate and deep cavities. In selected vital teeth, dentists may use selective caries removal, particularly near the pulp.

The peripheral part of the cavity is prepared so that the restoration can achieve an effective seal, while some affected dentine close to the pulp may deliberately be preserved rather than risking unnecessary pulp exposure.

Current evidence-based caries guidelines favour selective removal over routinely removing all carious tissue in many moderate and advanced lesions in permanent teeth.

What Happens When Tooth Decay Reaches Dentine?

Dental caries is a biofilm-mediated, sugar-driven disease involving repeated cycles of demineralisation and remineralisation.

Once a caries lesion extends into dentine, acids demineralise the mineral component while the organic dentine matrix can also become progressively damaged.

The pulp may react before bacteria physically reach it because bacterial products and inflammatory signals can travel through the dentinal tubules.

Treatment depends on the depth and activity of the lesion, whether a cavity has formed, the condition of the pulp and how much healthy tooth structure remains.

Does Dentine Decay Faster Than Enamel?

Dentine is less highly mineralised than enamel and has a different structure, so the caries process behaves differently once dentine becomes involved.

However, it is too simplistic to say that decay always “spreads rapidly through dentine”. Progression depends on factors including the activity of the caries process, diet, plaque biofilm, saliva, fluoride exposure and whether the lesion has been effectively sealed or treated.

Regular dental examinations can identify lesions before extensive tooth structure is lost.

Can Deep Dentine Decay Heal Without Root Canal Treatment?

Sometimes. A deep cavity does not automatically mean that root canal treatment is required.

If the dental pulp remains capable of healing, modern treatment aims to preserve its vitality whenever clinically appropriate. This may involve selective caries removal and a well-sealed restoration.

In certain situations where the pulp is exposed but still considered capable of recovery, vital pulp treatments may also be considered.

If the pulp becomes irreversibly inflamed or necrotic, however, root canal treatment may be necessary to preserve the tooth.

How Do Dentists Replace Lost Dentine?

Lost dentine cannot usually be biologically regenerated into its original external shape, so restorative materials are used when significant structure has been lost.

Depending on the amount and location of damage, treatment might involve:

• A composite filling
• An inlay or onlay
• A dental crown
• Other adhesive restorative techniques

Modern restorative dentistry generally aims to preserve as much healthy natural tooth structure as reasonably possible rather than removing additional dentine unnecessarily.

Can Fluoride Rebuild Dentine?

Fluoride does not cause a large missing piece of dentine to grow back.

However, fluoride can play an important role in controlling the caries process and encouraging remineralisation of mineral-depleted dental tissues. It can also help protect exposed root surfaces that contain dentine.

People at higher risk of decay or with exposed roots may sometimes be advised to use higher-fluoride products, depending on their individual circumstances.

Our guide to choosing toothpaste explains fluoride and sensitive-tooth formulations in more detail.

Can Sensitive Toothpaste Repair Dentine?

Desensitising toothpaste does not recreate missing dentine, but certain ingredients can reduce sensitivity by either blocking exposed dentinal tubules or altering the way sensitivity signals are transmitted.

Ingredients used in sensitivity products can include compounds such as stannous fluoride, potassium salts and other tubule-occluding agents.

These products generally need repeated use rather than producing an immediate permanent repair.

Can Exposed Dentine Be Covered Again?

Treatment depends on why the dentine became exposed.

If enamel has been lost because of erosion, wear or fracture, restorative treatment may sometimes be used to cover and protect the area.

If the root is exposed because of gum recession, treatment first involves establishing why the gum has receded. Some cases can simply be monitored and managed for sensitivity, while selected patients may benefit from periodontal grafting.

Glow Dental’s periodontal team can assess significant recession and exposed root surfaces.

What Is Sclerotic Dentine?

Dentinal sclerosis occurs when mineral is deposited within the dentinal tubules, making them narrower or completely blocked.

This process can occur gradually with ageing and can also develop as a response to chronic irritation.

Sclerotic dentine is less permeable than ordinary dentine and may therefore transmit stimuli towards the pulp less readily.

How Does Dentine Change With Age?

Dentine does not remain exactly the same throughout life.

Secondary dentine continues to form slowly, gradually reducing the size of the pulp chamber. At the same time, increasing mineral deposition within dentinal tubules can produce more sclerotic dentine.

These changes can make older dentine less permeable and sometimes less sensitive.

The colour of teeth can also become darker or more yellow with age because of changes within the dentine together with alterations in enamel and accumulated staining.

Why Is Dentine Yellow?

Dentine naturally has a more yellow or cream colour than enamel.

Enamel is partly translucent, particularly as it becomes thinner, so the colour and optical properties of the underlying dentine make a substantial contribution to the overall appearance of a tooth.

This is why teeth are not naturally paper-white even when they are completely healthy.

Does Teeth Whitening Whiten Dentine?

Yes, professional peroxide whitening can influence colour within the dentine as well as the enamel.

Hydrogen peroxide and peroxide released from carbamide peroxide are small enough to diffuse through dental tissues. Whitening works through chemical reactions involving coloured molecules within the tooth, including those associated with dentine.

It is therefore inaccurate to say that whitening works only by bleaching the enamel.

If you are considering whitening, read more about professional teeth whitening at Glow Dental and our guide to whether teeth whitening can damage teeth.

Can Whitening Make Dentine Sensitive?

Temporary tooth sensitivity is one of the most common side effects of peroxide whitening.

The mechanism is not simply that whitening “removes enamel and exposes dentine”. Peroxide can diffuse through the tooth and temporarily affect the pulp-dentine complex, which can increase sensitivity in some patients.

This does not mean that professionally supervised whitening routinely destroys dentine.

Read more in our guide to sensitive teeth during whitening.

Can Acidic Foods and Drinks Damage Dentine?

Yes. Dental erosion occurs when acids chemically dissolve mineral from the tooth surface without bacteria being the direct cause.

Once dentine becomes exposed, it is generally more vulnerable to acid attack than enamel because of its lower mineral content and different structure.

Frequent acidic drinks, sucking citrus fruits and other repeated acid exposures can therefore contribute to progressive tooth wear.

Acid reflux and repeated vomiting can also expose the teeth to stomach acid and may require both dental and medical investigation.

Can Brushing Damage Exposed Dentine?

Toothbrushing is essential for oral health, but aggressive brushing combined with abrasive products and an already softened or exposed root surface may contribute to wear.

You should not stop brushing exposed dentine. Instead, use an appropriate toothbrush, avoid excessive pressure and ask your dentist or hygienist to check your technique if recession or wear is progressing.

Our dental hygienists can provide personalised brushing and interdental-cleaning advice.

Dentine, Enamel and Cementum: What Is the Difference?

Tissue	Where it is found	Main role	Can it form after tooth development?
Enamel	Outer surface of the crown	Provides a highly mineralised protective and chewing surface	No biological regeneration once lost
Dentine	Beneath enamel and cementum	Forms most of the tooth and protects the pulp	Yes, secondary and tertiary dentine can continue to form internally
Cementum	Covers the root dentine	Provides attachment for periodontal ligament fibres	Continues to undergo limited deposition and repair

Can Scientists Regrow Dentine?

Regenerative dentistry is an active area of research. Scientists are investigating bioactive materials, growth factors, stem-cell approaches and tissue-engineering techniques designed to stimulate the pulp-dentine complex.

Some modern treatments can already encourage formation of a mineralised barrier during vital pulp therapy, but this is not the same as being able to biologically regrow an entire missing portion of a human tooth.

Claims that a toothpaste, gel or routine dental product can currently regrow a large cavity into a completely normal tooth should therefore be treated cautiously.

Frequently Asked Questions About Dentine

Can dentine grow back?

Not in the sense of replacing a missing section of tooth. However, a vital tooth can produce secondary dentine throughout life and tertiary dentine in response to injury.

Can a cavity repair itself?

An early non-cavitated caries lesion may sometimes be arrested or remineralised. Once a substantial physical cavity has formed, the missing tooth structure normally cannot regenerate itself and may require restoration.

Is dentine alive?

Dentine itself is avascular, but it is intimately connected with living odontoblasts and the dental pulp. Dentists therefore often refer to the biologically responsive pulp-dentine complex rather than describing dentine as an isolated inert material.

Is dentine softer than enamel?

Yes. Dentine is less highly mineralised than enamel, although its collagen-rich structure gives the tooth important resilience and helps support the enamel.

Can you see exposed dentine?

Sometimes. Exposed dentine may appear more yellow than surrounding enamel, but colour alone cannot reliably identify whether dentine is exposed or diseased.

Does exposed dentine always hurt?

No. Some exposed dentine is completely comfortable. Sensitivity is particularly associated with open dentinal tubules and rapid fluid movement within them.

Can sensitive toothpaste regrow dentine?

No. It may reduce symptoms by blocking dentinal tubules or modifying sensitivity mechanisms, but it does not recreate a missing piece of tooth.

Can fluoride regrow dentine?

Fluoride can support remineralisation and help control caries, but it cannot recreate a large area of dentine that has physically been lost.

Does tooth whitening work on dentine?

Yes. Peroxide can diffuse through enamel and dentine and alter coloured molecules within the tooth. This is one reason professional whitening can change the overall shade of natural teeth.

What happens if decay reaches the pulp?

The pulp may become inflamed as decay progresses. Whether it can recover depends on the severity of the inflammation and the clinical situation. If the pulp becomes irreversibly inflamed or dies, root canal treatment may be required.

How Can You Protect Your Dentine?

• Brush twice daily with fluoride toothpaste
• Use gentle brushing pressure rather than aggressive scrubbing
• Clean between your teeth every day
• Limit the frequency of sugary foods and drinks
• Avoid frequent acidic drinks and prolonged acid exposure
• Use a desensitising toothpaste if recommended
• Have persistent sensitivity investigated rather than assuming it is harmless
• Maintain healthy gums to reduce the risk of exposed root dentine
• Attend dental examinations at the interval recommended for you

Dentine Care at Glow Dental

If you have sensitivity, a cavity, tooth wear or exposed dentine, the first step is identifying why it has occurred. Glow Dental can assess the tooth during a dental examination and recommend treatment based on the cause rather than simply covering the sensitive area.

Small areas of damage may be treated with tooth-coloured fillings, while larger structural defects may require an inlay or onlay or another restoration. If decay has severely affected the pulp, Glow Dental also provides specialist root canal treatment in Battersea.

Patients with exposed root dentine caused by significant gum recession can also be assessed through our specialist periodontics service. If you are new to the practice, find out more about becoming a new patient at Glow Dental.

Summary: Can Dentine Grow Back?

Dentine has a limited biological ability to form new tissue, but a missing part of a tooth does not simply grow back to its original shape. Secondary dentine continues to form slowly throughout life, while tertiary dentine can develop internally in response to decay, wear or injury.

Demineralised dentine may also be capable of some remineralisation when its structure is preserved and the disease process is controlled. Established cavities, fractures and substantial wear, however, usually require dental treatment to replace or protect the missing structure.

The best strategy is therefore to preserve natural dentine wherever possible through fluoride, effective plaque control, conservative dentistry and early treatment of decay before extensive tooth structure or pulp health is lost.