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A person in a white T-shirt is holding their cheek with their hand – a typical gesture when one’s teeth are sensitive.A person in a white T-shirt is holding their cheek with their hand – a typical gesture when one’s teeth are sensitive.

Dentin hypersensitivity : Sensitive teeth – help and causes

Here’s what causes sudden, sharp toothache, and what you can do about sensitive teeth.  

Products for sensitive teeth
Updated on 21/05/26Find out more
Editorially reviewed
Scientifically reviewed

Anyone who suffers from sensitive teeth will know the sudden, sharp pain caused by a sip of hot tea, licking a cold ice cream or biting into a sour apple. Around half of all people are affected by sensitive teeth, known as dentine hypersensitivity, with some studies suggesting the number may be even higher.

In most cases, the reason for this sensitivity is exposed tooth necks: either the tooth enamel is damaged, or the gums have receded, leaving the dentine exposed. This allows stimuli to be passed directly to the nerve – sometimes visibly, but often only detectable by a trained dental eye.

In this article, you’ll find out about the most common causes of sensitive teeth, effective ways to prevent them and important treatment options.

Bioniq® Repair Toothpaste Plus Acute Sensitive

Toothpaste containing 20% biomimetic enamel (hydroxyapatite/HAP) for daily oral care and reducing sensitivity

Bioniq Repair toothpaste with gum protection, in blue and white packaging and a tube, both featuring a pink plus sign.
  • Reduces sensitive teeth by occluding exposed dentinal tubules
  • Forms a protective layer on the teeth
  • Gentle cleaning with mild abrasives

Background : Why do teeth suddenly become so sensitive?

There are various reasons why teeth hurt. Most people probably think of tooth decay first. However, teeth are even more likely to hurt when the dentine is exposed. 

In healthy teeth, the dentine is protected by the enamel above it and surrounded by the gums. The dentine is criss-crossed by many small, fluid-filled channels – known in technical terms as dentinal tubules. These tiny channels transmit stimuli to the inside of the tooth, known as the pulp. The pulp is the ‘centre of the tooth’ and consists of numerous fine nerves and blood vessels. 

An overview of the key structures: 

  • Tooth enamel:
    The hard, protective outer layer of the tooth that shields the sensitive dentine from irritants. 

  • Dentin:
    The layer of the tooth beneath the enamel, containing many fine tubules (dentin tubules) that transmit stimuli. 

  • Pulp (the inside of the tooth):
    The soft inner part of the tooth, containing nerves and blood vessels, which sends pain signals to the brain. 

Microscopic image of tooth structure with open tubules, overlaid with yellow flashes – symbolising the transmission of pain in sensitive teeth.

If the enamel is damaged – especially around the edge where the tooth meets the gum – or the gum has receded, the dentine is exposed. When you consume hot or cold drinks or foods, thermal stimuli are then passed directly to the pulp via the dentinal tubules. The nerves there immediately signal the sudden, sharp, stabbing pain to our brain.

But it’s not only cold or heat that can trigger this pain. Certain foods can do so too, usually acidic or sweet foods. This is known as a chemical stimulus. Just like thermal stimuli, these are passed on to the pulp via the fluid-filled dentinal tubules.

Causes : Causes of sensitive teeth

There are a number of possible causes of sensitive teeth. These can be divided into four categories: 

  • Category 1 : Erosion:

    These are enamel defects caused by chemical processes, meaning acid-related enamel loss.

    The acids may come, for example, from foods and dissolve minerals out of the tooth. If this happens continuously, the enamel becomes thinner and thinner, and the tooth neck becomes exposed.

  • Category 2 : Abrasions:

    Here, too, the tooth enamel is affected. However, the damage is caused by mechanical forces, i.e. pressure or friction. 

    Brushing too vigorously, for example, or using the wrong toothpaste can wear away the enamel – effectively sanding it down. Here, too, the areas around the neck of the tooth are often affected, leaving the dentine exposed. 

  • Category 3 : Recessions:

    The term describes (non-inflammatory) gum recession. When the gums recede, the neck of the tooth—and therefore the dentine—is exposed. 

  • Category 4: Gum disease:

    Inflammatory gum diseases in particular, such as gingivitis and periodontitis, cause the gums to recede. This also results in exposed tooth necks.

Go directly to the section: Help with sensitive teeth

Reason 1 : Acidic drinks and foods

Anyone who loves fizzy drinks, fruit juices and energy drinks won’t be pleased to hear this. With long-term consumption, acidic drinks demineralise the enamel, making it porous and increasingly thin. Microscopic cracks form, making it less able to protect the dentine and tooth nerves from thermal or chemical influences. Unlike tooth decay, these erosions are not caused by acids produced by bacteria, but by acid attacks of non-bacterial origin.

As well as acidic drinks and foods, stomach acid can also cause hydroxyapatite crystallites to gradually dissolve out of the tooth enamel. This means reflux, frequent vomiting during pregnancy or bulimia may also be possible causes of sensitive teeth.

Reason 2: Poor oral hygiene

There are various bacteria in the mouth that are essential for healthy oral flora. However, with the wrong or an unbalanced diet, harmful bacteria can dominate in the biofilm. These produce certain substances that cause the gums to become inflamed. Bacterial plaque builds up particularly well between the teeth and along the gumline. If it is not removed by daily brushing, gingivitis often develops in these areas. As a result of the inflammation, gum recession often follows.

Many patients who suffer from sensitive teeth or gum problems tend to brush their teeth less, or stop brushing altogether. This is problematic because plaque builds up continuously, hardens and turns into tartar, which can only be removed by a dentist. The gum inflammation can also worsen and develop into periodontitis. Periodontitis affects the entire tooth-supporting structure, including the bone, and cannot be reversed, but requires lifelong treatment. Patients with periodontitis often have sensitive tooth necks.

  • Did you know?

    It isn’t just natural teeth that are prone to plaque. Bacteria can also collect along the gumline around dentures and dental restorations, which can encourage exposed tooth necks where these are still present.

Reason 3: Incorrect toothbrushing technique

However, tooth enamel and gums can also be damaged by excessive care. Some people take dental care a bit too far: they want to be thorough and end up pressing the toothbrush too hard against their teeth. If the toothbrush still has stiff bristles, or if brushing takes place too soon after eating acidic foods, the damage usually outweighs the benefits. 

Using the wrong technique when brushing your teeth can literally wear away the enamel and damage the gums. As a result, the necks of the teeth are exposed, leading to sensitive teeth. If your gums bleed during your daily oral hygiene routine, this is an early sign of gum inflammation or an incorrect brushing technique. Either way, this should be checked by a dentist. 

Reason 4: Teeth grinding

Mechanical pressure can also cause sensitive teeth, for example when the teeth constantly rub against each other due to teeth grinding. This constant strain usually results in tooth damage, which can appear in very different ways. However, dentine is often exposed here too, and reacts painfully to stimuli.

What makes it particularly tricky is that many people clench their upper and lower jaw together unconsciously, often at night. Dentists diagnose this teeth grinding as what is known as bruxism. The pressure created by teeth grinding is often many times higher than the pressure used when chewing food, and usually lasts much longer too. Tooth enamel cannot withstand this kind of strain in the long term.

  • Other mechanical damage: 

    Tongue or lip piercings can also cause problems. As the metal inevitably comes into contact with the teeth and gums, this can cause damage over time, making the teeth hypersensitive. 

Reason 5: Dental treatments

Some patients complain of sensitive teeth, particularly after treatment at the dental practice. However, this is usually a normal reaction that disappears again after a short time. Increased sensitivity is particularly common after: 

  • Professional teeth cleaning (PTC) 
  • Dental restoration procedures, such as a crown or bridge 
  • Periodontal treatment 
  • Teeth whitening 

During a professional teeth cleaning at the dentist’s surgery, tartar and bacterial plaque are removed from the gum line. This can cause slight irritation to the gums. This is inevitable – no matter how skilled and experienced the dentist is. However, the treatment is essential for gum health, which is why you should not skip your professional teeth cleaning. Furthermore, any discomfort usually subsides after a short while. 

Reason 6: Teeth whitening

Methods for making teeth whiter are now no longer carried out only by dentists. There are also various tooth-whitening treatments for use at home. During bleaching, the teeth are usually whitened with hydrogen peroxide. This substance removes not only unwanted discolouration from the tooth, but also fluid. The enamel is temporarily “dried out”, so to speak, and the gums can also become irritated. When saliva and fluid come into contact with the tooth again, patients often feel pain. This usually subsides after a few days.

Patients who already suffer from sensitive teeth should always discuss tooth-whitening measures with their dentist. Otherwise, the sensitivity may worsen further.

11 tips : What can be done to relieve sensitive teeth?

A black-and-white photograph of molars with yellow streaks running across them – symbolising tooth sensitivity.

Avoiding hot and cold foods and drinks and consuming only lukewarm ones is not a long-term solution for most people affected. There are a number of things those affected can do to combat tooth sensitivity and start enjoying all foods again. 

Whether at home or at the dentist’s, the best way to minimise sensitivity is to take care of your teeth and gums. 

The following 11 tips can help with sensitive teeth: 

  • Tip 1: Protection provided by tooth enamel

    A toothpaste containing ‘artificial enamel’ helps to reduce sensitivity. It contains hydroxyapatite, which is modelled on our natural enamel.  

    Studies show that hydroxyapatite is the most effective ingredient in dental care products for reducing tooth sensitivity. With regular use, microscopic defects responsible for transmitting sensitivity are sealed, and the enamel surface is repaired with every brush. 

  • Tip 2: Make mouthwash part of your daily routine

    A mouthwash not only freshens your breath, but also removes bacteria from hard-to-reach areas that can lead to receding gums.  

    Unlike mouthwash, mouth rinse is supplied ready-to-use in the recommended dosage and does not need to be diluted. Solutions that contain not only antibacterial agents but also hydroxyapatite provide additional strength to the tooth surface and help prevent tooth sensitivity. 

  • Tip 3: Be careful with whitening toothpastes

    Toothpastes designed to whiten teeth contain a high proportion of abrasive particles, which, whilst they remove plaque, can also damage the tooth structure.

  • Tip 4: Less pressure when brushing your teeth

    The right brushing technique can make a significant difference for sensitive teeth. This is because people often apply too much pressure when brushing or scrub vigorously back and forth with their toothbrush.  

    It is better to brush from red to white using less pressure – that is, from the gums towards the teeth. Also pay attention to how you hold the toothbrush. If you clench your hand into a fist, you will quickly apply too much pressure. It is better to hold the manual toothbrush with just your fingertips to avoid causing damage whilst brushing. 

  • Tip 5: Choosing the right toothbrush

    Gentle brushing is easier with a toothbrush designed for sensitive teeth. However, choosing the right one is not straightforward and should be done in consultation with the experts at your dentist’s surgery. 

    After all, even soft bristles can cause abrasions. Some electric toothbrushes are also fitted with sensors that warn you if you’re applying too much pressure. However, even in this case, leaving the brush on a tooth for too long can damage the enamel. 

  • Tip 6: Put yourself in the hands of dentists and dental professionals

    Make sure you attend your regular check-ups at the dentist. This allows dental problems, gum inflammation and exposed tooth necks to be detected at an early stage, so that appropriate treatment can be initiated.  

    If you have already noticed that your teeth are sensitive, please speak to your dentist or dental hygienist about it. They can identify the exact cause – for example, abrasion, erosion or recession. 

  • Tip 7: Use a mouth guard to stop teeth grinding

    If you suffer damage caused by unconscious or nocturnal teeth grinding, a mouthguard or ‘grinding guard’ can help.  

    It is custom-fitted to your teeth by your dentist and is therefore comfortable to wear. The mouthguard acts as a buffer between the chewing surfaces, reducing friction and protecting the tooth surface. Some health insurance providers may even cover the full cost of its manufacture. 

  • Tip 8: Sealing of exposed tooth necks

    Exposed tooth necks are not covered by hard enamel and are therefore particularly sensitive.  

    To protect the dentine from external irritants, dentists can seal it with a special varnish or gel. Studies show that products containing hydroxyapatite are the most effective.  

    In the case of so-called wedge-shaped defects, a composite resin filling can also be used. 

  • Tip 9: Give up smoking

    Smoking not only has a negative impact on health and the cardiovascular system, but also on the teeth.  

    The gums receive less blood flow and become prone to inflammation. As a result, they recede, which contributes to dentine hypersensitivity. 

  • Tip 10: Avoid acidic foods

    As acids make tooth enamel porous, patients with sensitive teeth should try to cut down on acidic foods. These include soft drinks, coffee, citrus fruits and various berries such as raspberries, blackberries and redcurrants.  

    Foods high in sugar should also be eaten less frequently, as the sugar is also converted into acid by the bacteria in the mouth. 

  • Tip 11: Tips for reducing acidity

    It is impossible to completely avoid consuming acids through food. What’s more, acidic fruits such as cherries, kiwis and the like also contain other important nutrients.  

    You can at least mitigate the effects of acid to some extent. For example, by eating wholemeal products, you can stimulate saliva production, which helps to neutralise the acid. Alternatively, you could drink a glass of milk or have some natural yoghurt with your fruit. The calcium found in dairy products also helps to neutralise acids. 

Exception : Special case: A single tooth that is sensitive or sensitive to pressure

A black-and-white image of teeth showing an enlarged, circled area highlighting details and fine cracks in the enamel.

In some cases, pain when eating has nothing to do with dentine hypersensitivity in the classic sense. If only a single tooth reacts sensitively regardless of food, or if teeth hurt particularly under the pressure of chewing, tooth decay or pulpitis may also be the cause of the sensitivity:

  • Tooth decay: develops when bacteria metabolise food residues, especially sugar, into acids. So, if a lot of sugar is consumed, the bacteria have plenty of food and produce a corresponding amount of harmful acids. Eventually, the tooth becomes so damaged that a cavity forms, which can only be treated with a filling by a dentist. The further the decay progresses, the more likely pain is to be felt.
  • Pulpitis: is inflammation of the dental pulp and is often commonly referred to as root inflammation. If tooth decay is not treated, bacteria can reach the pulp and cause inflammation. Pulpitis can also occur after a dental injury or after a dental crown has been fitted. In cases of pulpitis, the dentist usually carries out root canal treatment.

Bioniq® : Products for sensitive teeth

Bioniq® Repair Toothpaste Plus Acute Sensitive

Toothpaste containing 20% biomimetic enamel (hydroxyapatite/HAP) for daily oral care and reducing sensitivity

Bioniq Repair toothpaste with gum protection, in blue and white packaging and a tube, both featuring a pink plus sign.
  • Reduces sensitive teeth by occluding exposed dentinal tubules
  • Forms a protective layer on the teeth
  • Gentle cleaning with mild abrasives

Knowledge : Other topics

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  • A white powder surface with the word ‘Bioniq’ embossed on it, symbolising hydroxyapatite as a dental care ingredient.

    Hydroxyapatite – the active ingredient behind strong tooth enamel

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Dr. Joachim Enax

Senior Scientist Oral Care

Dr. Joachim Enax is an expert in biomimetic oral care and oral health. As a PhD chemist, he is an experienced scientist in the research and development of innovative active ingredients for oral care and in promoting dental health. He is the author of numerous scientific publications in the field of teeth and oral care.

Scientifically reviewed
Verified on 21/05/26

Karoline Bauch

Corporate Communications Officer

Karoline Bauch is an expert in science communication specialising in the Oral Care sector and acts as the editorial contact for all matters relating to dentistry, oral health and prevention.

Editorially reviewed
Verified on 22/04/26